Torque Converter Lock-up mods any BTDT

[SUMOTOY]

What happens when you are decellerating down a slope and you need to tap the brakes? With this mod it sounds like when you touch the brake pedal, the truck is going to surge forward when the TC unlocks. Sounds ugly. The way it's set up now it's fairly predictable. Also, you'd lose the extra torque provided at the higher RPM's when climbing an obstacle, unless you shut it off. My first impression is that this mod would not be desireable.

-Spike

My first impression is that anyone that is changing differential gear ratios and claiming downhill 'gains' ought to seriously consider how a torque converter works, and a lockup mod benefits over stock Trans torque converter operation. If *all* you do is use it for downhill, the gains are significant, to the claimed gearing gains, and to the longevity of the trans. BTW, the new Tundra and LC have lockup torque converter operation in first gear low....

I suppose you could theorize how scarey it would be, doesn't appear that scarey to me, more like 'predictable'. 'Up to' 1.8:1 energy stored in a torque converter doesn't sound more predictable, and 'up to' 1.8:1 by definition adds undesireable overrun torque during compression braking. "Surge forward.." sounds much more dramatic than reality. This guy's 40 looks pretty hardcore on the same trails many here are familiar with
http://www.usedcarsplus.com/classic-cars/03-use/toyota/280272387419.html
http://meerobus.googlepages.com/home
I find it interesting that new trucks have fully integrated this feature as part of "hill descent" mode. I'm just convinced it doesn't need to have a computer attached to make it beneficial to an 80

YOMV

Scott J

 

[-Spike-]

Sounds to me like you might want to get some seat time before you start postulating on how scary a forward surge might be in certain situations. When you're decending a ~35 plus degree rock slope with decomposed granite under your tires (ex. the 'Luge' on the Martinez Mine trail in Az), trying to keep the speed at ~1-2 ft/sec, any sudden change in speed is likely to cause you to lose traction and therefore control of the vehicle. If you're relying on the engine braking effect to slow you down but gravity overcomes it, you'll have to ease into the brakes. If the TC unlocks as your foot grazes the pedal and lights your brake lights, you'll have a surge in forward momentum that you likely will not be able to recover from. Of course, that's probably what all those silly electronics and software are for on newer vehicles.
The only way I can see this being viable is if the TC release was tied to brakes + idle, and there's probably more to it than that. And you've completely ignored the benefits of having a slushbox, which among other things include smooth transitions from idle and increased torque from a standstill. I'm sure there are a few people that have done this mod, and they're probably happy with it, but I personally don't see the benefits. Your assertions that the transmission would see less stress and last longer are moot, since we don't see too many transmission failures or overheating issues.

-Spike

 

[Tools R Us]

... When you're decending a ~35 plus degree rock slope with decomposed granite under your tires (ex. the 'Luge' on the Martinez Mine trail in Az), trying to keep the speed at ~1-2 ft/sec, any sudden change in speed is likely to cause you to lose traction and therefore control of the vehicle. ...

-Spike

What your saying that you wouldn't want a system jerking around on this? Wuss!

 

[SUMOTOY]

Sounds to me like you might want to get some seat time before you start postulating on how scary a forward surge might be in certain situations. When you're decending a ~35 plus degree rock slope with decomposed granite under your tires (ex. the 'Luge' on the Martinez Mine trail in Az), trying to keep the speed at ~1-2 ft/sec, any sudden change in speed is likely to cause you to lose traction and therefore control of the vehicle. If you're relying on the engine braking effect to slow you down but gravity overcomes it, you'll have to ease into the brakes. If the TC unlocks as your foot grazes the pedal and lights your brake lights, you'll have a surge in forward momentum that you likely will not be able to recover from. Of course, that's probably what all those silly electronics and software are for on newer vehicles.
The only way I can see this being viable is if the TC release was tied to brakes + idle, and there's probably more to it than that. And you've completely ignored the benefits of having a slushbox, which among other things include smooth transitions from idle and increased torque from a standstill. I'm sure there are a few people that have done this mod, and they're probably happy with it, but I personally don't see the benefits. Your assertions that the transmission would see less stress and last longer are moot, since we don't see too many transmission failures or overheating issues.

-Spike

I don't believe on descents many understand what a torque converter is doing. It's slipping - *always*. And during descents then by definition the chances of an unlocked torque converter overrun are greater. And the 'benefits' of compression braking are less. If you are less than 3mph or under 2150rpm, you have *less* consistent torque than if you had a locked out torque converter. I equate that concept to better control in *my* seat time, YOMV. And I think you have the "surge" scenario exactly backwards-wrong.

I say if you really want to claim that diff gearing is actually helping compression braking on a downhill, minimally this mod would need to be installed first. It also appears to be rather straight forward to install and compare. I don't do much rockin anymore, cuz I think my 4R was better suited to it. But it sure appears a serious 40 rock crawler has installed it in the links above, and claimed the same benefits that Rodney puts forth in the marketing of the mod. Since it would appear no one here has any btdt with an 80 here, it's interesting to see all the reasons not to do it. I tend to believe this is from not many folks here understanding how a torque converter operates during wheeling.

Again, I'm sure I have this wrong, but might be worth a try. Seems a lot cheaper than a gear swap to me, even if you bought Rodney's revalving package.

Cheers

Scott J

 

[SUMOTOY]

What your saying that you wouldn't want a system jerking around on this? Wuss!

I like pretty pics of 80's wheeling. Then again, comparatively speaking, if you take a look at that FJ40 link of the meerobus above, I don't believe there are many 80's on this list that are close to as well rigged for crawling, including a twin stick NP205 and 37's... And the guy uses a torque converter lock during downhills for the same reasons I claim, Rodney markets, and math might confirm.

And he also has action pics of his rig too.

Cheers

Scott J

 

[Tools R Us]

I don't believe on descents many understand what a torque converter is doing. ...

I will be the first to admit that I don't fully understand the inner workings of a torque converter. Have done enough playing with fluid dynamics to know that it's often not intuitive, but that's immaterial to how it reacts on the trail.

I know how it worked on the decent pictured, the setup is trans first, transfer low, CDL locked (some would correctly argue that it should be open, I didn't see the need for this hill). Brakes controlling speed all of the way, throttle just above idle most of the way down, as I came to the first hole (~15' ahead of Spike with the black tire rubber marks) I throttled up slightly. The throttle is for two reasons, first; going to need to maneuver, so want plenty of steering assist. Second; the decent is off camber to driver, the big hole is hidden by the branch, when the driver tire drops into it, we're going much more off camber, the passenger rear will rise, if the driver rear looses traction it will come around and the only way to save it from rolling into the wash below, is instantly throttling out.

So the torque converter was loaded in forward all of the way down, it's effect was about zilch. Unless you have a light rig with a crawler box your not going down it without brakes. If you would like to demonstrate some other torque converter action on it, come on down, it's great wheelin weather, that hill is in a scenic, fun wheelin area close to town.

 

[Tools R Us]

I like pretty pics of 80's wheeling. Then again, comparatively speaking, if you take a look at that FJ40 link of the meerobus above, I don't believe there are many 80's on this list that are close to as well rigged for crawling, including a twin stick NP205 and 37's... And the guy uses a torque converter lock during downhills for the same reasons I claim, Rodney markets, and math might confirm.

And he also has action pics of his rig too.

Cheers

Scott J

It's fun to web wheel, but remember that wheeling is different everywhere. Most Aussies use their rigs very differently than most of us do. In Arizona we are very lucky, loads of good wheeling, in very different terrain, from mountain forests to dunes. When I go one state away to Utah, have to reset my butt meter, the techniques/lines that work in Moab wont work here and vice-a-versa.

Here is a pic of a cool local rig, one of tons of them around here, they are extremely capable in the rocks. When we are on the trail, even the same obstacle, the line that works for my rig, probably wont work for his and vice-a-versa.

What makes the '80 great is what it can do. For example Sean and I go to Moab, his has to be on a trailer, mine holds all of the junk for the week and is driven. On the way I wheel every opportunity, often leaving the highway and rejoining 50mi apart, he can't due to the trailer. Would also submit that his rig wouldn't be the most enjoyable thing to run 60mi trail day, even less with weather. When we get to Moab, he can run all of the trails, I can only about 90% of them.

Could I modify my rig to run all of the trails he does, not going to happen, could probably get to 95%, but at what compromise? The '80 is great because it a Swiss army knife of wheeling, it's comfortable on the highway, long trail days and effective on most 4+ trails. If you try to make it something it's not, you compromise what it's great at.

What works great on one type of rig, place, terrain, driver, etc may not work well/at all in another. So discussion of what works on other types of rigs is about as relevant to what works on an '80 as what works on a bicycle!

 

[SUMOTOY]

Again, I enjoy wheeling shots, but in my experience I know that the stills don't tell a fraction of the story, btdt many times. WRT "different" wheeling everywhere, I don't agree. If we specifically look at downhill 'slow races', I believe you don't think the unlocked torque converter did squat, I bet it didn't. And I believe it would do "more" if the TC was locked. That's not complicated fluid dynamics, it just means if you lock the torque converter, you 'effectively' lock the engine to the gears. That has benefits in all types of wheeling.

Again, I look at the FJ40 above, and it sure appears his goal was to make a dual purpose truck, and he even speaks to that aspect as goal of the build. As I read thru the recent claims on the gearing thread before this, it became obvious to me that there appears to be a basic misunderstanding of how torque converters work. Would love to do a Torque Converter 101, but I know better. Instead, I just searched for a guy that owns a toyota, crawls regularly with it, has every offroad gizmo installed, and he runs a locked torque converter. Dunker. Aussie? No, Rubicon, Moon Lake, Loon Lake, Coyote Lake.

Here, on this list, you would be hard pressed to find less than a handful of Tranfer Case mods. That doesn't bother me in the least. But, if the given modus is 2.488 Transfer Case, and Tire equivalent gearing, this Torque Converter mod looks to be all wins, and worthy of serious consideration. I know the 80 can do great things offroad as a stock truck, btdt. I toss this potential mod up to *help* those that may think that great things are happening because of axle gearing. IMO, you won't put that size gear in the axle to make enough of a difference.

I have no pressing interest to do this Torque Converter mod for offroad prowess, but I would bet anyone that even occasionally crawls with an 80, or does a long downhill, or found brake fade crawling in those phenomenal 80 brakes, would not only find it beneficial, but comparatively inexpensive way to improve offroad performance in a dual purpose 80.

I'll take every hard knock on this thread, and the gearing thread before. I think I also clearly understand how a torque converter works, more specifically, how it doesn't and why. Makes me wonder why this forum-owning the king of the pigs, has never used a lockout torque converter wheeling. *Then* tell me it's bs. The pretty pics and 'what-ifs'? Just do it, I bet no one takes the mod out. At worst, just identifies where it has the best benefit.

Cheers

Scott J
94 FZJ80 Supercharged

 

[-Spike-]

Time and again you will tell us that what works for us doesn't really work, and that we obviously don't understand the dynamics of whatever situation we're discussing. Don't try to pull the 'I'll take every hard knock on this thread' card here- no one has given you any. We've all been quite civil with you, despite your condescending tone.

I will go out on a limb and guess that any rig taking advantage of a locked torque converter in low/low has an extremely low final drive gear ratio. Same as a manual tranny rig has to have low gears or burn the clutch. The torque converter takes the place of the clutch in those situations, and does it well. You have yet to show a reason that this mod is necessary, nor explain how it would be beneficial over the stock setup with stock gearing. Installing a 'clutch' pedal that could incrementally unlock the torque converter might solve some of the issues, but introduce others.

It doesn't take a genius to figure out what could happen to a vehicle that lurches on a downhill trail. Your mod as you have described it would introduce that lurching between the time you hit the brake pedal and the time the brakes actually engage. Can you address this assertion? So far you have completely ignored it.

After you explain that, perhaps you could be bothered to explain where I'm going to get enough torque to drive up an 18 inch ledge at idle with a locked torque converter and stock gearing.

-Spike

 

[Ebag333]

It doesn't take a genius to figure out what could happen to a vehicle that lurches on a downhill trail. Your mod as you have described it would introduce that lurching between the time you hit the brake pedal and the time the brakes actually engage. Can you address this assertion? So far you have completely ignored it.

Now, I don't know much about torque converters, other than what I've learned from Wikipedia and such. So perhaps the way I understand it is incorrect.

Anyway, if we're assuming a locked TC, then the fluid is going to be spinning at an approximately close rate to what the TC is spinning at (yes?). If the TC suddenly unlocks for some reason (like say hitting the brakes), the engine side of the TC will actually slow down, because most times when you hit the brakes you're letting up on the gas.

But lets say you're double footing, so you're applying skinny pedal (a more common scenario in wheeling). This means that the engine side of the TC will speed up, and start accelerating the fluid. This of course means more torque to the transmission.


But this is where I get hung up. In a way, it's somewhat similar to a super/turbo charger spinning up and dumping air into the motor. But the catch is that there is a delay between the spin up (be it the blower or TC) and the dump of fluid.

In my little I-don't-understand-torque-converters-that-well world, this delay would be far more than enough time for the brakes to engage before the fluid "dumps" and the extra power is applied.

Yes, you will get a sudden surge of torque, but I wouldn't think you'd get a lurching between the time you hit the brake and the brakes actually engage.

Plus, how often are you going to be unlocking the TC while suddenly hitting the skinny pedal? Wouldn't you need *LOTS* of extra RPM's to make a big enough lurch (dump of power)?

After you explain that, perhaps you could be bothered to explain where I'm going to get enough torque to drive up an 18 inch ledge at idle with a locked torque converter and stock gearing.

Correct me if I'm wrong, but won't the engine stall if you're at idle with a locked TC? (Same as trying to stop/idle with the clutch engaged on a manual.)

 

[Tools R Us]

...
Correct me if I'm wrong, but won't the engine stall if you're at idle with a locked TC? (Same as trying to stop/idle with the clutch engaged on a manual.)

Correct, with a heavy rig and no crawler box the gear ratio is relatively high, so slip is needed to go slow enough. When climbing would stall or have to hit the obstacle too fast. See it all of the time, standard trans rigs, FJC's mini's, etc, ether slipping the clutch or stalling. Down hill, like the hill pictured, standard rigs are ether on the brake, chugging the motor or in the case of the one with us the clutch was depressed and used the brakes, ether way it's brake dependent.

Using the brake, I come off of this one clean, can slowly lower it down. If relying on gear, even if the rig had a manual would be too fast and would slam down, contacting exhaust, rocker, etc.

 

[Ebag333]

Correct, with a heavy rig and no crawler box the gear ratio is relatively high, so slip is needed to go slow enough. When climbing would stall or have to hit the obstacle too fast.

In that case then a fully locked TC would be essentially useless for low speed crawling, as you'd stall all the time.


Now, Sumo keeps mentioning 8 different lockup modes. What are the 8 different modes? Is there such a thing as a partial lockup?

 

[-Spike-]

If the TC suddenly unlocks for some reason (like say hitting the brakes), the engine side of the TC will actually slow down, because most times when you hit the brakes you're letting up on the gas.

In my scenario, you're going downhill using the locked TC and engine to slow the vehicle. Your foot is not on the gas, the truck is being kept at a slow speed by the resistance of the engine. If the grade was steep enough to cause the vehicle to go faster than you desire, you'd have to hit the brakes. Sumotoy's mod would have the TC lockup disengage when the brake pedal is depressed, assumably using the brake light circuit as the trigger rather than brake fluid pressure. The brake light circuit is engaged at the very top of the pedal travel, while brake fluid pressure doesn't build up until the pedal is well down. That means the TC would disengage, allowing the vehicle to succomb to gravity and lurch forward before the brakes actually begin to work. Jamming on the brakes quickly to avoid that lurch is not intuitive, nor conducive to a safe descent in certain situations. Having the truck surge forward could build up enough speed and/or momentum to make control difficult or impossible, depending on the terrain.

-Spike

 

[Tools R Us]

Let me try an example that maybe closer to your understanding. Say your ice racing, taking a turn at the very limit of adhesion, would you want the trans to suddenly downshift? My guess is that your doing everything possible to be as smooth and predictable as possible?

Now look at the pic, his driver front is only touching the sidewall, passenger front only a tiny spot of tread and sidewall, passenger rear about to be in a low traction spot, The “rock” looks to have plenty of grip, but is very loosely held together, I call it ball bearing rock, it has a lot of grip to a point, then the little nodules fracture off, become bearings and you slide until you hit flat. So he is doing everything possible to be as smooth and predictable as possible. He is watching the directions from the spotter and creeping smoothly forward, if he makes any sudden movements he’s sliding down and it wont end well.

These examples have a lot in common, both cases are high adrenaline with rig, personal damage is at risk, and both require lots of seat time to be done well. One is done at high speed, the other at maybe inches per minute.

 

[Tools R Us]

Like I said, this was one of the first mods that I looked into, thought is would have promise, until I got some seat time in the rig and learned the advantages of an auto in a heavy rig. Having slip is a great thing, allows it to do things that a manual couldn’t and do them smoothly with great control, so why would one want to go backwards? Having slip also dampens drive train shock, helps greatly in preventing breakage and extends part life, a great thing in a heavy pig. If there were a readily available crawler box that didn’t require cutting up the rig, then I may change my view point, probably not, but as it stands I don’t see any benefit to it on the ’80 for wheeling?

That said, for long hills like this, if your loaded, towing a heavy trailer it may be beneficial? I shifted 2nd and rolled leisurely down it, don’t think I hit the brake, except to stop and take pix, enjoy the scenery.

 

[Ebag333]

In my scenario, you're going downhill using the locked TC and engine to slow the vehicle. Your foot is not on the gas, the truck is being kept at a slow speed by the resistance of the engine. If the grade was steep enough to cause the vehicle to go faster than you desire, you'd have to hit the brakes. Sumotoy's mod would have the TC lockup disengage when the brake pedal is depressed, assumably using the brake light circuit as the trigger rather than brake fluid pressure. The brake light circuit is engaged at the very top of the pedal travel, while brake fluid pressure doesn't build up until the pedal is well down. That means the TC would disengage, allowing the vehicle to succomb to gravity and lurch forward before the brakes actually begin to work. Jamming on the brakes quickly to avoid that lurch is not intuitive, nor conducive to a safe descent in certain situations. Having the truck surge forward could build up enough speed and/or momentum to make control difficult or impossible, depending on the terrain.

-Spike

Okay, I can understand your concern.

You gotta remember though, the TC will work both ways, even unlocked. That is to say, the fluid in the TC will resist change to a certain extent. Since we have the TC locked, the fluid is essentially spinning at the same speed as the engine/tranny. When the TC unlocks, it's not going to let the tranny instantly speed up.

I think you're thinking of it as completely engaged or completely disengaged. But it's really more like a manual transmission, where it's more akin to pressing on the clutch at a relatively slow speed.

So yes, you are going to lose your engine braking, but you won't lose it complete and you won't lose it instantly.

Now, of course, the multi million dollar question is....how long does the TC take to to overcome the inertia of being locked, and is that slower or faster than it takes for the brakes to engage?

I'm not sure anyone can answer that one without actually doing the mod and testing it out. Personally I think that the brakes will engage before the inertia in the TC is overcome, but that's purely a guess.....

Let me try an example that maybe closer to your understanding. Say your ice racing, taking a turn at the very limit of adhesion, would you want the trans to suddenly downshift? My guess is that your doing everything possible to be as smooth and predictable as possible?

I'm not sure how your example/point applies (or even what point you're exactly trying to make ).

Having the TC unlock and the transmission downshift are two very different things. (Assuming you were actually trying to relate the two.)

A fully locked TC means that the slightest pressure (or easing up) on the skinny pedal will have a direct effect on your tire rotation. An unlocked TC means that there's lots of slip, and things will be much more smooth.


Now, honestly, I can't see where a locked TC would be useful in the majority of rock crawling. I can see where it'd be useful in coming down a hill, for the purpose of engine braking, but once you get down towards idle speeds you have to unlock the TC anyway or risk stalling the motor.

The only purpose I can see for a locked TC would be in cruising on the freeway, and downhills. With downhills for wheeling, you're already in low gear and have quite a bit of engine braking, so a locked TC is of limited use (especially at the speeds most people are going down tricky spots on).


I guess the real question is the cost/difficulty of the mod. I wouldn't mind doing it for the relatively rare occasion I'd use it if it was about the same cost as say the CDL switch.

 

[Tools R Us]

Let me try an example that maybe closer to your understanding. Say your ice racing, taking a turn at the very limit of adhesion, would you want the trans to suddenly downshift? My guess is that your doing everything possible to be as smooth and predictable as possible?

I'm not sure how your example/point applies (or even what point you're exactly trying to make ).

Sorry it was an admittedly crude attempt for Sumo, he doesn't wheel , but ice races, was hoping it would be something that he could relate to?

… A fully locked TC means that the slightest pressure (or easing up) on the skinny pedal will have a direct effect on your tire rotation. An unlocked TC means that there's lots of slip, and things will be much more smooth.

Now, honestly, I can't see where a locked TC would be useful in the majority of rock crawling. I can see where it'd be useful in coming down a hill, for the purpose of engine braking, but once you get down towards idle speeds you have to unlock the TC anyway or risk stalling the motor.

The only purpose I can see for a locked TC would be in cruising on the freeway, and downhills. With downhills for wheeling, you're already in low gear and have quite a bit of engine braking, so a locked TC is of limited use (especially at the speeds most people are going down tricky spots on).

I guess the real question is the cost/difficulty of the mod. I wouldn't mind doing it for the relatively rare occasion I'd use it if it was about the same cost as say the CDL switch.

I agree, the theory here is that it would only require an relay, wire and switch, I was going to control it with a momentary switch on the steering wheel, so would be cheap to try. If you surf some of the Aussie forums there are several who have done it, IIRC they all dropped and modified the valve body to get it to work in first. Not something I wanted to do, mine works fine. They reported that it is of little use for wheeling and engagement/disengagement is sometimes abrupt in low range.

IIRC the good posts were on 4x4 weekly forum? They bunch all rig models together by brand, making searching, surfing time consuming. I may have the links on the home PC, will look over the weekend.

 

[SUMOTOY]

In my scenario, you're going downhill using the locked TC and engine to slow the vehicle. Your foot is not on the gas, the truck is being kept at a slow speed by the resistance of the engine. If the grade was steep enough to cause the vehicle to go faster than you desire, you'd have to hit the brakes. Sumotoy's mod would have the TC lockup disengage when the brake pedal is depressed, assumably using the brake light circuit as the trigger rather than brake fluid pressure. The brake light circuit is engaged at the very top of the pedal travel, while brake fluid pressure doesn't build up until the pedal is well down. That means the TC would disengage, allowing the vehicle to succomb to gravity and lurch forward before the brakes actually begin to work. Jamming on the brakes quickly to avoid that lurch is not intuitive, nor conducive to a safe descent in certain situations. Having the truck surge forward could build up enough speed and/or momentum to make control difficult or impossible, depending on the terrain.

-Spike

In your scenario, your foot would already be on the brake = NA. You can't "drive 1-2 miles per hour" with torque applied as that's below the truck speed at idle. See gearing thread. Even if you want to claim higher mph to claim your point, it's not crawling by definition, and the benefits of the TC lock become better, and the risk of stall becomes less. The locked TC will have more negative engine torque, so less braking, and longer cycle between braking. By defnition a torque converter locked>disengaged *or* just unlocked --- neither is doing anything below the truck speed at idle. More basic argument, an unlocked torque converter "lurches" less than a locked torque converter, and by definition, no more than it does without the mod?

In that case then a fully locked TC would be essentially useless for low speed crawling, as you'd stall all the time.

I say you disengage it with a braked relay ala Rodney's kit. A fully locked TC is only useless below the truck speed at idle. But, the good news is a fully *unlocked* TC is useless below the truck speed at idle too.

Now, Sumo keeps mentioning 8 different lockup modes. What are the 8 different modes? Is there such a thing as a partial lockup?

<edit> I'm confusing folks on my reread of this thread, as I am speaking to the input matricies vs lockup on the 442, lockup is a switch gate, either locked or unlocked. Interrupt at the computer allows us to modify the conditions of that on/off signal.

Sorry it was an admittedly crude attempt for Sumo, he doesn't wheel , but ice races, was hoping it would be something that he could relate to?

That's just funny. Kevin, I have a lot of wheeling experience in an autobox, 3 different trucks, thanks. And see aboslutely the benefits of a TC locking during downhill, especially a long steep downhill. I hit brake fade in my 4R AT crawling many times, and wished for something better than the 4.30 gears in the truck. I've wheeled in my 80, and got close to brake fade with the stock weight of the truck and stock tire weight. Made me majorly cut back on the habit, as I know for a fact the 80 has some of the best brakes in any sport utility.

Mod benefits to a low geared truck? Say what? If we look at speed as x feet per second to stall point, how can a guy like meerabus above be fast enough on the left pedal to disengage the TC during wheeling as not to stall then? Again, 'looking at it', then doing nothing is fine with me. But many/most of the arguments you guys present, don't appear to be 'looking at it' in terms of how the TC works. I see no benefit in trying the mod then either.

Scott J
94 FZJ80 Supercharged

 

[RedTacoma]

strange

First thing first. I rather replace gears then busted clutch pack in tranny because I locked TC and used 150K miles clutchpack to slow down 6000 lb beast with over sized tires and stock gears.

Now this is where the advice of lower gears in axles comes in. get them if you planning on long descents, also make sure your tranny has proper level of ATF (Amsoil or Mobil). Make sure cooling is running right and if you live in hot climate Aux tranny radiator with separate fan may be good idea.

Let TC work as hydraulic retarder for you and you will be fine.... Thats why Toyota designed them like that. We dont drive FORDs
I trust my yota and so far I never was dissapointed.

 

[-Spike-]

I guess it's me that doesn't wheel. I've never experienced brake fade on my 80, 40, nor my Nissan P/U. I use engine braking whenever possible, only touching the brakes when necessary. The only vehicle I ever experienced brake fade in was a Starion, when braking from high speeds. I did see someone else in an 80 experience brake fade, but it was after following him over a few miles of hilly dirt road, with his brake lights on for every downhill portion.

-Spike