Diff drop...Slee or BIOR?

[Live to Ski]

First (and most important): Zappa....a card well played LandCruiserPhil!

Second: that whole drop and drive shaft angle situation(no pun there)...never thought of that and makes sense.

Third: Non drop CV angle w. lift situation...wouldn't the sharper angle combined with load be an issue...especially under high load, low rpm, max droop as is encountered on trail? Kinda sorta similar to the birfield failures of previous generation LC front ends? May be different design, but gotta imagine...Plus, on highway, I bet the non-dropped lifted dif cv angles are withing design envelope of non lifted rigs.

To make a short story long...er long short: I am now, thanks to this thread, in the non-drop camp. Take the $ and .

 

[BlueWeim]

FWIW i spoke with an extremely knowledgeable sales person for the OME lift before purchasing and he told me the upper control arms arent a bad idea, but the diff drop isnt worth buying. He said the only reason they sold them was to make some extra profit because they dont make much off of there OME/ARB products. He said the OME is designed to run without the control arms and diff drop, if they thought it needed it they would include it in their kits.

OME seems to have things figured out and know what they are doing so I took his word.

Makes sense to me?

 

[cc93cruiser]

"Say no to diff drops!"- the truth is out...

 

[sleeoffroad]

A diff drop is certainly not required, but it does not hurt anything (other than maybe the wallet). In the 100's of trucks we do, we have not experienced driveline vibrations with the diff drop.

Having the CV angles less is always a good thing on a IFS truck. The 100 is unique and should not be compared to other Toyota IFS trucks where a diff drop is really just a rotation of the diff and can cause pinion bearing lubrication issues. With the 100, the diff is dropped straight down.

Yes, it is an extra part we sell, but we will always tell you it is not required, but we prefer to install them. As for OME having it figured out, ask them if they can align any of their supposedly 3" kits on Toyota IFS trucks to spec without aftermarket upper arms (either adjustable or fixed added caster) and see what they say. Then go and do it in practice and see what happens. All I will say we learned a lot after we installed our own alignment rack.

So just because OME does not include it doesn't mean that it does not have a benefit. Just like the upper arms they do not include.

Phil posted the low cost DIY route for those that do not want to spend the money.

 

[TRAIL TAILOR]

A diff drop is certainly not required, but it does not hurt anything (other than maybe the wallet). In the 100's of trucks we do, we have not experienced driveline vibrations with the diff drop.

Having the CV angles less is always a good thing on a IFS truck. The 100 is unique and should not be compared to other Toyota IFS trucks where a diff drop is really just a rotation of the diff and can cause pinion bearing lubrication issues. With the 100, the diff is dropped straight down.

Yes, it is an extra part we sell, but we will always tell you it is not required, but we prefer to install them. As for OME having it figured out, ask them if they can align any of their supposedly 3" kits on Toyota IFS trucks to spec without aftermarket upper arms (either adjustable or fixed added caster) and see what they say. Then go and do it in practice and see what happens. All I will say we learned a lot after we installed our own alignment rack.

So just because OME does not include it doesn't mean that it does not have a benefit. Just like the upper arms they do not include.

Phil posted the low cost DIY route for those that do not want to spend the money.

Christo, I'm happy to spend 250$ on not only a good sound quality product, but also a component that will help alleviate future maintenance costs. I'll be calling Monday to order a couple of items.

The diff drop won't be going on this first round temporary lift (1.25"), but will added for sure on the new Flexi-Coil suspension in the near future once it arrives (3.0")

Thanks,

Jason

 

[Hayes]

I don't know what you guys are smoking.
Since I installed my diff drop I'm getting 30 mpg, 50 extra horsepower, 100 ft/lbs of torque, and I can drive grade 8 trails without lockers.

 

[BlueWeim]

I don't know how to quote, but to Christo, I wasn't saying they had the 3" figured out. Ha. That's why none of my trucks have ever had anything bigger than a 2 and leave the torsion bars within a reasonable tolerance...

And I can't really say one side or the other. I have a Slee diff drop in my garage waiting to go on my truck and the SPC upper control arms on my truck with a 2" lift. I was just referencing what I was told by another company and patting OME on the back for having great products.

Either way, its not required. I've had trucks with and without the diff drop. I'm kind of a preventative maintenance person myself so adding longevity to CV's was peace of mind when lifting my newest cruiser.

 

[LandCruiserPhil]

I don't know what you guys are smoking.
Since I installed my diff drop I'm getting 30 mpg, 50 extra horsepower, 100 ft/lbs of torque, and I can drive grade 8 trails without lockers.

Please share what you are smoking because it seems to be working GREAT. Whos diff drop did you purchase and does it come with an O.pen to make installation easier? Hmmm Slee is in Colorado, right?

 

[TRAIL TAILOR]

Please share what you are smoking because it seems to be working GREAT. Whos diff drop did you purchase and does it come with an O.pen to make installation easier? Hmmm Slee is in Colorado, right?

Sign me up too

IIRC... I had a vision with MIND RAPE!, THEY'RE COMING THEY'RE COMING.... or was it ... THIS IS PERMANENT!

I'll take some more please!

AND ALL SMOKE PASSES THROUGH WY NOW IT SEEMS!

J

 

[YardPig]

Since we're mentioning names in the diff drop arena, and went with Chris's chromoly drop, nice piece!

For Sale: - 100 Series Land Cruiser Front Diff Drop Kit

 

[Live to Ski]

From my (caveat: verrrry limited experience) point of view: is it easier to remove/replace u-joints (diff drop/drive shaft perspective), or remove/replace (or re-grease/re-boot) cv joints (non diff drop/CV perspective)? Really interested in the answer here.

Thanks in advance & great discussion.

 

[YardPig]

I think it's easier to install a diff drop and forget about your cv's and boots...

 

[benc]

Like cristo said, the less angle you have on the cv the better.
Certainly not needed but it will prolong the life on the boots and cv joints.
Again totally different than a Tacoma or 4Runner diff drop,
I opted not to install one on my Tacoma because it does cause major issues with the driveshaft, on the LC, it does drop the entire diff straight down and maintains a propper driveline angle. This is also the reason why you can get a diff drop for a Tacoma for $30 and the LC diff drop is $250, the Tacoma is a few longer bolts and spacers, the LC includes a new crossmember. With the price involved to build and produce the diff drops I can guarantee the vendors that sell them are not getting rich off of these.

 

[DirtDawg]

What I want to know is who has proven incidents showing that boots/CVs wear faster without a diff drop than with one? The driveline vibes/u joints are not a concern as we have clearly seen many people with them installed here and they have no issues. I was simply comparing the 4Runner/Tacoma in the same manner that they reduce the CV angle. But I have yet to see evidence to support everyone claims.

I'm sure these guys aren't making a ton of profit on these and I'm not trying to hurt anyone's business, I just want people to make educated decisions before they purchase. And to me I have seen that these are unnecessary, if anyone has proof otherwise please say so.

 

[benc]

The Benefits highly depend on the lift height and type of driving, if you put a lot of freeway miles and you lifted 2 1/2" the problems will show them selfs much quicker than if all you do is drive back roads at slower speeds and are lifted 2". More angel = more friction = more wear.
I guess the only way to prove it would be to run the exact same setup on the same roads for the same miles to see who has problems first.
Some times you can actually see where the the cresses on the boots are rubbing each other due to the steeper angles, this will cause the boots to tear prematurely, one experiment one could do (a little harder on full time 4wd) is jack up the tire as far out on the a arm as possible and rotate the tire by hand, the jack up be the center crossmember so the suspension is dropping and rotate again, you will notice the tire is considerably harder to turn and you can even hear the boots rubbing together,
This is where the more angle, more friction more wear comes into play.

 

[DirtDawg]

The Benefits highly depend on the lift height and type of driving, if you put a lot of freeway miles and you lifted 2 1/2" the problems will show them selfs much quicker than if all you do is drive back roads at slower speeds and are lifted 2". More ange= more frictions = more wear.
I guess the only way to prove it would be to run the exact same setup on the same roads for the same miles to see who has problems first.
Some times you can actually see where the the cresses on the boots are rubbing each other due to the steeper angles, this will cause the boots to tear prematurely, one experiment one could do (a little harder on full time 4wd) is jack up the tire as far out on the a arm as possible and rotate the tire by hand, the jack up be the center crossmember so the suspension is dropping and rotate again, you will notice the tire is considerably harder to turn and you can even hear the boots rubbing together,
This is where the more angle, more friction more wear comes into play.

I agree with all your above points. They've all been considered and noted. But we have members on here running high miles on their lifted rig without a diff drop and no cv issues to speak of. So what miles are we expecting to see this wear? 250k? At that point I'm gonna be re-booting/replacing CVs regardless. So I'm looking at a real world perspective.

Is a diff drop good? Sure, it slightly reduces the CV angle on lifted rigs and can possibly help extend the life of your boots/CVs. But are they necessary? No. That has been my point all along.

 

[SWUtah]

Hell its worth it just to have it in my signature . I have 22k on the lift on my 100, when the drivers side large boot started oozing some grease. Guess I could of just rebanded it because the boot was fine but I had it rebooted by my Lexus dealer because I like their cookies. Mine is a Mall cruiser.

 

[SmoothLC]

^ I like the way you roll @SWUtah. #talkingstraight

 

[Live to Ski]

benc: Don't get how dropping the dif straight down maintains DS angles. Wouldn't the angles be steeper (greater). My only experience (as in contemplation) is straight axle ds and lifting. As I recall, at greater lifts, the DS angles are too steep (@ both the tcase & axle interface), thus the need (maybe perceived) for shims.

Open for an education here....

 

[benc]

benc: Don't get how dropping the dif straight down maintains DS angles. Wouldn't the angles be steeper (greater). My only experience (as in contemplation) is straight axle ds and lifting. As I recall, at greater lifts, the DS angles are too steep (@ both the tcase & axle interface), thus the need (maybe perceived) for shims.

Open for an education here....

Yes, the drive shaft will be slightly steeper but dropping the diff straight down maintaines a propper angle. On a driveshaft witout a cv joint at one end the the pinion flange must remain at the same angle as the output on the transfer case, this is what makes the diff drop on the LC different, the entire diff gets lowered which lowers the cv axels the same amount while not really changing the pinion angle.
On other vehicles the diff drop only drops the front of the diff, thus changing the pinion angle, causing driveline vibrations and only drops the cv axles by about 1/4".
With 2" and under lift I would consider it not necessary but helpful, anything over 2" I personally would run a diff drop in the 100.
Do I have proof? No, but with an understanding of how the axels work I know the diff drop is going to extend the life on a lifted 100.
I do know of one instance where a friend of mine without a diff drop had just installed nitro upper control arms and icon shocks, he is only lifted about 2", he was driving through a ditch on his property to test out the new suspension and over extended his brand new oem cv which alowed it to bind up and snap. Would a diff drop have prevented this? Maybe, maybe not but another aspect to consider is if there is ever any plans to install extended travel suspension the cv may not be able to handle more travel without lowering the diff.