need serious advice on trans/tcase/front diff. issues (1 Viewer)

[edwards_rljr]

ok... first a little background... I have a '78 FJ40 and I just spent about $2300 having my transmission, t-case and clutch rebuilt.. my mechanic told me that all my tranny gears were in good shape so the rebuild consisted of all new bearings and seals, gaskets, syncros AND that $500+ ring assembly because he said he would not do the rebuild unless I replaced that too... my t-case idler gear set and high speed gear had chips in the teeth and needed to be replaced.. I bought good used gears for that and a new bearings, seals, and gasket kit... new bushings for the gears that had them were also bought and taken to a machine shop to be pressed in and machined to fit the shaft... all new aisin clutch parts... when he put everything back in, it was still up on the lift and he started it up and let it run for a while with no load.. shifted through the gears and everything seemed fine... took it down and went for a drive and he said there was an obvious whine that he thinks is coming from the t-case... I've driven it now, and the whine is very obvious and much worse than any whining that I had heard before the rebuild.. he said that everything was within specs but he thinks it might be because the used idler gear set and high speed gear came from another t-case and even though they looked to be in good condition, they were originally in another case with other gears that they were originally matched with or wearing against for however many years so they could be meshing with the others a little differently now and causing the whine... does anyone have an opinion on this issue? All I know is that I was expecting it to be quiet after spending all this money on the rebuild... and this is a very significant whining in my opinion.

Also, when he drove it, he was shifting through the gears and shifting into 4wd and said it will shift into 4 wheel low and high fine but then will not shift back out ... he put it back up on the lift and it will shift out of 4wd fine.. shifts in and out of 4wd fine on the lift with no weight on it but if it's on the ground it will not shift back out of 4wd... he says that he thinks something is binding the front driveshaft at the front differential... has anyone ever heard of this problem ? any ideas ?

Also, this probably sounds bad, but due to a lot of different factors, mainly not having money to fix broken stuff and not having time to go 4 wheeling anywhere, I had not even had it in 4wd in over 2 years before I took it to him for the rebuild so I don't know if this was a problem before the rebuild or not.. I used the 4wd over 2 years ago when it last snowed here (in Georgia) and it shifted in and out fine then... any advice or opinions would be appreciated.

 

[Fast Eddy]

I've got a rebuilt case in mine that whines too. Probably the same problem. I paid $200 and put it in myself. I don't mind it too much, and I think it's getting quieter, but I don't put that many miles on it.

As for the 4wd binding, it sounds like your mechanic is tired of working on it. I hope you haven't paid him yet.

I suppose it could be bound up if you were in a turn on pavement. Do you have locking hubs? What happens if you unlock the hubs first, drive a bit, then try shifting out of 4wd?

 

[Pighead]

The "not being able to shift OUT of 4wd" seems pretty common among LandCruisers...
Try putting it in reverse when that happens, on the ground, not on the lift, pop the clutch, drive it backwards a few feet and see if that helps.

 

[rchandler]

Dump the lube , check for chunks or metal flakes ' put in some Redline 75-140 , thick floor mat and run it . Good luck

 

[Josie'sLandCruiser]

Hi All:

I'm no expert on gearbox re-builds, but from what I've heard mating used gears together will result in gear whine, until the gears wear into each other.

In my experience with a part-time four wheel drive system often one must drive in reverse to get the t-case to dis-engage the front drive shaft (i.e. four wheel drive.)

I'm sorry you've spent $2300 to get the gearboxes re-built. Labor is *expensive!*

Good luck!

Alan

 

[KY854RUN]

A good friend of mine, who is a full time 4x4 mechanic, had the same gear whine problem in his FJ40. He had done a hasty rebuild of the transfer case in his 40 so that we could make it to the TLCA Rubithon. He had combined the gears from 2 T-cases to make the one. The whole way there it whined horribly and on the way home it was only a little better. He said that he should have taken the time to sandblast the gear teeth, of all of the gears, to remove their original wear pattern. This would have prevented the loud whining. We were both a little tone deaf for a while after that trip.

As far as the shifter problem, I have heard that if the linkage is installed backwards, it can cause this problem.

 

[Bodean]

A buddy built mine a few years back with parts from 2 cases. Metal in the oil every time I have changed it but no whine. It's been wheeled about 8 times hard with no issues. I'm gonna wheel it till it quits and then go Orion. I say change the gear oil and drive it.

Later,

 

[KOOTENAY KRUZER]

With my 40s I find that if it doesn't want to come out of 4wd, get at least one wheel on something with less than perfect traction (like a gravel shoulder), accelerate gently and then back off, all the while pushing the tc lever towards 2hi, it should move quite easily just as you back off the throttle, the key is to have some slippage so the drive train doesn't bind and do it while the vehicle is in motion in a straight line. Do Not try to go from lo to hi or vice-versa while moving, though.

 

[Weedhopper]

Me too. I have to I have to put the transmission in 1st and put pressure on the T case lever into 2hi. When I start moving it slips in to 2hi.

 

[brider]

shifting 4W-2W

To elaborate on what has already been mentioned:

Your mechanic's opinion that it's something in the front differential says to me that he has no knowledge of a simple driveline design, or just wants to blame something that's his fault on something he didn't touch.

Or, your front drive collar is binding on the front output shaft (within the t-case)when there's the slightest torque load on the front. The torque load while on the lift is almost non-existent.

Shifting out of 4WD with your mechanical lever on the floor (mine is a vacuum shift, so if it binds, the only way to un-stick it is to back up/turn/forward/etc until it pops out) is simply move the lever IN or OUT. If it won't MOVE OUT, then try backing up like the others said. It's a simple collar that slide front/back to engage the front or not.

UNLESS, he somehow installed the shift fork in the t-case nose housing BEHIND the collar, in which case the shift fork can push the collar INTO 4WD, but not pull it back out. I'm not sure if this is possible on a floor shift, but I did it on my vacuum shift ONCE.

I can't see how sandblasting can remove any wear pattern from the hardened surface of a carburized gear.

 

[KY854RUN]

To elaborate on what has already been mentioned:

Your mechanic's opinion that it's something in the front differential says to me that he has no knowledge of a simple driveline design, or just wants to blame something that's his fault on something he didn't touch.

Or, your front drive collar is binding on the front output shaft (within the t-case)when there's the slightest torque load on the front. The torque load while on the lift is almost non-existent.

Shifting out of 4WD with your mechanical lever on the floor (mine is a vacuum shift, so if it binds, the only way to un-stick it is to back up/turn/forward/etc until it pops out) is simply move the lever IN or OUT. If it won't MOVE OUT, then try backing up like the others said. It's a simple collar that slide front/back to engage the front or not.

UNLESS, he somehow installed the shift fork in the t-case nose housing BEHIND the collar, in which case the shift fork can push the collar INTO 4WD, but not pull it back out. I'm not sure if this is possible on a floor shift, but I did it on my vacuum shift ONCE.

Brider is right on this, your mechanic does not truly understand the drive-train of your FJ40. If he did, then he would not be shifting it into 4 wheel drive while on dry pavement. Even on gravel roads I have had to back up or make a turn to get my truck out of 4WD.

Driving an FJ40 in 4WD on dry pavement will cause the drive-train to bind up. And if driven long enough, will cause the truck to stall out or worse, brake something in the drive-train.

I doubt that the T-case is assembled incorrectly, because it does shift in and out of 4WD on the lift without any trouble.

I can't see how sandblasting can remove any wear pattern from the hardened surface of a carburized gear.

This really does work. The friend that I mentioned, took his T-case apart after the trip and sandblasted the gear teeth. He reassembled the T-case and the whine was gone. Now, bead-blasting won't work because the glass beads are not hard enough to abrade the surface of the gears.

 

[Doug_S]

I agree with the others where the mechanic doesn't understand the LC's drive train. The way I look at it is " Oh Well" it looks like the guy who "rebuilt" the trans and transfer case has some more work to do. Check the clutch disengagement as well. If the clutch is not disengaging then it will be difficult to shift in and out of 4x4.

 

[Mr. Toad]

Your mechanic's opinion that it's something in the front differential says to me that he has no knowledge of a simple driveline design, or just wants to blame something that's his fault on something he didn't touch.

Brider is right on this, your mechanic does not truly understand the drive-train of your FJ40. If he did, then he would not be shifting it into 4 wheel drive while on dry pavement. Even on gravel roads I have had to back up or make a turn to get my truck out of 4WD.

I agree with the others where the mechanic doesn't understand the LC's drive train.

Any third grader could understand the drive train of an FJ40. I'm sure the mechanic does too.

However, as KY854RUN said, the mechanic shouldn't have driven it on pavement in 4wd. Doing that causes a bind-up (just as the mechanic said), and the binding is even related to the front driveshaft (sort of like the mechanic said).

Here's the deal: Your FJ40's 4wd t-case has no differential like an AWD vehicle's t-case has. In 4wd, the FJ40 t-case turns the front and rear driveshafts in exactly a 1:1 ratio to each other. However, the front and rear axles do not cover distance in a 1:1 ratio; for instance, the front axle takes corners wider than the rear axle does. So if the t-case is forcing a 1:1 front:rear ratio at the same time that the axles are doing something else, the t-case gears bind and you can't operate the t-case selector.

This is not a problem on loose surfaces where less-than-full traction allows the tension to release. If it binds, bump the car around a little (put in gear, reverse, whatever) or lift a wheel. In any event, that part of your experience is not a problem.

 

[1973Guppie]

on the whining, it is from the different gears not meshing correctly, I used good used gears in my TC when it was rebuilt and it whined for a few years, it is now much better, put some miles on it, it should be fine in my opinion.

my 40 never wants to come out of 4x4 after wheeling, some aggressive reverse and forward motions while turning the wheel usually allows it to pop out, again, fairly normal.

 

[edwards_rljr]

thanks for everyone's input

I really appreciate the input and opinions on this because it's had my worried sick after I've spent all this money and thought that it just wasn't right...

I did not know this mechanic before he started working on my FJ40 but he was the only guy in my area that even acted like he could or would rebuild my trans/t-case.. he told me that he had been rebuilding manual tranny's for years but didn't have any experience with landcruisers but was confident that he could do it.. and after I found out that my tranny gears were in good shape and the t-case only needed the idler and high speed gears replaced, I decided I would rather spend a little more having mine rebuilt so that I would KNOW that I was getting all brand new koyo/nachi bearings,etc. and that it would hopefully last for years to come instead of buying someone elses used trans/t-case and not really knowing what I was getting... I let him use my factory manuals so he would have all the technical info/specs, etc.. and he seemed like a stand up guy and I don't think he's trying to screw me over or anything.. he just has a small garage , not a big corporate chain place... so you guys are right that he's not really familiar with the drivetrain, but I think that was just an honest mistake... I had forgotten about the whole 'needing to back up a little to take it out of 4WD' thing ... after reading that here, I remember reading that somewhere a long time ago and I had actually done that the few times I've actually ran it in 4WD (and not on dry pavement.. I had read that before too) and I guess I should've clarified in the first post, but he didn't drive down the highway in 4WD.. that was just in his parking lot that he was trying it out to see if everything would shift ok... I can't believe that I didn't remember about having to back it up when he told me about the problem.. I guess I've just been so stressed out and worried that something was going to go wrong that it slipped my mind.. LOL... looks like problem solved on that issue...

It sounds like the majority opinion on the whining is that it's being caused by the mixing of the t-case gears from what was still good in mine and the idler gear set and high speed output gear that I bought used... this makes me feel a little better about the situation although I'm not happy at all about the loud whining... I wish I had known about this beforehand so I could've got them sandblasted... I don't know if my mechanic would be willing to tear it back down for that without charging me a lot more money... I may just have to live with it for now anyway... from what you all have said, it sounds like the noise is the only real issue with this and is not really going to do any damage, right ? and it will hopefully just go away as they develop a new wear pattern ? hopefully it will...

thanks to everybody that replied to my post.. I appreciate it.

 

[Pighead]

Another closely-guarded secret ...these transfer cases are pretty easy to take apart and put back together.
If the whine gets too much for you, you've got the manuals, just follow along the numbered steps. No need to pay a mechanic for that.

 

[edwards_rljr]

really ?

I didn't think it was something I would be able to do myself... I was under the impression that you couldn't just take a trans or t-case apart and put it back together with new bearings,etc. like other stuff I've done... I was under the impression that the gears had to be 'set' a certain way.. within specific tolerances or whatever... that's why I didn't even try to do it myself.. I have done a lot of work on my cruiser myself.. such as rebuilding the steering knuckles, pulling all the axles and replacing axle bearings and seals, swapped out the rear differential, rebuilt the brakes, put on a weber 38mm carb. kit, poly gas tank, electric fuel pump, pointless distributor, new heavy duty radiator,etc. but I have no experience with gears and such and I had done some reading on rebuilding the differential when I was having problems with that and it sounded very complicated.. backlash, bearing preload,etc... that coupled with the cost of a ring and pinion was the reason I just bought a good used diff. and swapped the whole thing out ... so I figured I wouldn't be able to do the trans/t-case rebuilds myself either ... I wish I could have.. would love to learn how to do that stuff.

 

[Pighead]

If you know which end of a wrench to hold, you can rebuild a transfer case. The hardest part is separating it from the transmission...
You can do knuckles? You can do a transfer case.

 

[1973Guppie]

I would just drive it , the whine will go away over time as the gears mesh....

 

[kiwidog]

TC whine

Hi Edwards,

The transfer case whine on the early transfer case( not split) is caused IMHO by the intermediate gear. This the gear in the middle of the three. It is there to make the output shafts rotate in the same direction as the engine and get the lower range when it is selected. The intermediate gear has bushings installed on the inside and it rotates on the intermediate shaft. As the bushing wear a little the gear cocks over a bit and the pattern on the tooth mesh with the other gears is not optimized. When you are off the gas and in coast mode there should also be a whine, maybe not as much. When you are in coast mode and they is no weight on the driveline in either direction it will be quiet. When you mate new gears too a used gear by replacing parts either brand new parts or "new" used parts you will get a whine untill you have a few miles on the beast and the parts mate with each other.
One thing that was probably over looked when it was repaired were the bushings in the intermediate gear and the intermediate shaft. If the is excessive clearance between those you will get more whine as you go from power to coast with silence (as quiet as an FJ40 can be) in between.
If it was assembled right them I would just drive it and as has been said before the whine will probable get a little less over time.

Thanks jb