Toyota Celica Supra Forum banner

Rear axle noise from lowered suspension?

5K views 42 replies 11 participants last post by  battleaxe 
#1 ·
Well, I haven't posed a off the wall question in a bit of time. Been getting some clunking noises from the rear, low speed, often when turning. Feels a bit like drivetrain getting locked up or twisting? So I started searching for info on the wonderful internet, and found that some trucks make a somewhat similar sound from the slip yoke not being able to slide in and out of the tranny smoothly. Then I wondered about my rear half shafts, maybe at the lowered stance of my car, the CV joints are complaining? I figured others have lower cars than mine, those rear axles are angled a bit upward (from diff to wheel hub), thought maybe they need to be rebuilt. My rear axles have never been serviced, about 188k miles now.

Oh yeah, single aluminum driveshaft, r154 tranny, trutrac LSD presently.

Anyway, the noises bother me, and I always (now) worry about stuff breaking when I get on the power (1jz).

Any thoughts, much appreciated!

Don L.
 
#3 ·
I'm with him, back that thing up on some ramps and give everything a yank. Maybe the input of your diff is funky? Big power guys upgrade those, word on the street is the mk2 size is not quite big enough? I could be way off base as i'm going off my forum whoring, regardless solid yanking on everything while on ramps should find if you have anything loose.
 
#4 ·
Thanks guys, I really need to do some diagnosing. Thing is, when the car is up on ramps, yanking on parts usually shows things are tight, but perhaps because they have some tension. I can only eliminate the LSD and housing because the noises seem consistent despite swapping diffs.

Mostly low speed, take off, moving around parking lots. It actually feels to me like a locker rear end and the two rear wheels are fighting each other. Have a truetrac in there now, and it should be the smoothest unit available in my garage. No locker action at parking lot speeds.

Right now thinking driveshaft spline into tranny, rear half shafts, the 2 subframe mounts above the diff.

I really need the car to be smoother. The car is powerful, suspension is stiff, but the knocking and rattle noises bother my focus and enjoyment of the car.

I see those clearance prices of 2014 Focus ST models for $20k and sometimes it's tempting!

Don
 
#5 ·
You might take the axle bolts off and inspect the cages. Those that have broken axles its usually that part that fails. If its when turning I would put my money on axles or rear diff.

It could also be your rear driveshaft u-joint the small Mk2 joints aren't that strong. But you'll usually get that when only when speeding up and slowing down.

BTW The seating position is terrible in the Focus. It feels like you're sitting in a minivan. It has nice seats though.
 
#6 ·
The aluminum driveshaft has upgraded u-joints, and pinion flange is upgraded to a Toyota truck size (or Mk3, not sure now). The axles, well, they are kinda old and been beaten to death. I guess there are rebuild kits for the CV boots ?
 
#9 ·
I didn't see your post until after I jabbered about axel shafts.$75 a side is a bargain!
I want the ones with the shiny BLUEBoots!Mine are probably worn out by now.I should have replaced them when I had my pumpkin out.
 
#8 ·
When you lowered the car,the axel shafts angles changed.The CV joints may be popping in and out of their usual wear area . The joints "wore in" at the former angle and now the joints are at a slightly different angle. The CV balls may be rolling into and out of the old wear area. I didn't price-out a pair of rebuilt axel shafts for you.
 
#10 ·
My car makes these noises in parking lots and such, but I have a welded diff, haha. I wouldn't think it would be the tranny yoke cuz with IRS the diff and driveshaft assembly never move. On trucks, they have straight axles so when the rear end changes height, the whole driveshaft moves with it. So, I'd say definitely diff, axles or blown out subframe bushings.
 
#11 ·
Check your rear hubs for play in the splines. My mild 5mgte bent the teeth on mine enough to cause 10-15 degrees of play. I'm not sure they will last much longer behind the LS but I have all the parts ready to go whenever they finally completely shear.
 
#12 ·
Hmmm, play in hub splines? Gotta check that. Not sure I would get the clunking, popping noises though. Still, with this car's history, lot of stuff could be on the verge of breakage.

Thanks for the thoughts guys! Good point about the yoke shouldn't be moving much. I guess mostly likely problem is in the wonderful rear area.

Don L.
 
#14 ·
Fast forward to October 2016, at a autocross at Crows Landing, huge concrete site, fast course, speeds up to probably 80 mph in the car (past events here got up to 110 mph in 3rd gear). Broke the driver side inner CV joint on rear axle. At least I have spares, so back home and 8 nuts later, we are good.




This particular fail is new to me. Now I am familiar with another potential weakness in my overstressed drivetrain. The CV cage was busted to pieces, balls everywhere, splined shaft as seen got pretty well honed. I attribute this to the large power, 315 rear race tires, and my Kaaz LSD that was locking up too soon thus stressing the axles. I have since tuned the LSD (diff) to have more "differential" action, basically allowing opposite rear tires to turn at different speeds at low throttle and mid throttle. At full throttle the LSD would still fully lock and both rear tires will want to turn at same rate (ala locker). I have always heard that best way to break rear 1/2 axles is by using a locker. With enough tire slippage, no problem (like drifters), but my setup is not drifty, so I learn a bit more of the cars limits. Less preload, slower rate of lock. I'm getting it :)

Don L.
 
#16 ·
I would have to say the rear end is quieter now, not exactly sure why since a few other things have changed too. Currently have the OS Giken LSD on the car. Initially (after some machine work) it was locking up very hard, then after several adjustments by OSG, it now seems to work more like how everyone who raves about these units describe it. Smooth and quiet on slow turns, progressively increases lockup with added throttle. Gets full lockup at full throttle. I guess for now, can't ask for much more. Now other areas of suspension need attention.

Back to the original question, the axle that broke never felt like it has excessive play in the CV area, as I checked it by hand, but maybe there was enough tension I could not tell if there was play.

Yeah, the 315 Hoosiers in rear are just the ticket to bust up more parts in the drive train. So far, just ring/pinion gear, and a single axle. As long as a stub axle doesn't break, most everything else I can swap ok.
 
#17 ·
Gee,the Internet is slow tonight. (Friday evening)
How does the OS Giken LSD 'tighten' up at higher throttle application/RPM's?
Moreover,how does it allow loose diff-action in low speed turning?
How does it do that,please?
Does it require a special lubricant and what do the manufacturers recommend?

I run the OEM LSD and the(Ford) additive is critical in it's function.
 
#18 ·
http://www.motoiq.com/MagazineArtic...rt-2--Tuning-a-Limited-Slip-Differential.aspx

Above is a link to one of the very few good articles describing how an OSG LSD operates. They cost a bunch, and adjustments and tuning of the LSD is usually done by OSG in S. Calif. Private shops usually cannot "tune" the OSG units as parts and such is controlled by OSG. Yeah, a bit exclusive, and limiting at times, but they do try hard to work with the driver to get the LSD tuned to the situation. That article can describe the OSG better than I can.

Very simply, the OSG units have more friction plates, for better lockup and smoother lockup. There are different cam ramps available which can dictate how gradually the lockup comes. There are springs, actually 2 kinds of springs that control preload of the plates, and another kind of spring that prevents lockup of the plates. This last type of spring is unusual in that keep the plates from locking, essentially makes the unit an open diff, good for turning, no chatter, etc. However, these unlocking springs eventually get overcome by the preload springs and action of the cam ramps that with torque from throttle will force the friction plate together.

It's all really foggy to me, but I have a Trutrac, a 1.5 way Kaaz, and a 1.5 way OSG. All great units, but I believe if the OSG is tuned correctly, it will work the best and last the longest before requiring a rebuild.

The other LSD I would look into if I needed to blow more cash, is the Cusco unit. It sounds very adjustable, and parts are available for the owner to make the changes, kinda nice.

Don L.
 
#22 ·
I read all of the pages,and I'm blown away!
Quote:
However, these unlocking springs eventually get overcome by the pre load springs and action of the cam ramps that with torque from throttle will force the friction plate together.

Cam ramps set the clutches load at torque,not RPM, dictates the clutch lock up/slip mode.
ingenious!
I'm impressed,totally.
That was a GREAT read! Thank you,sir.
 
#19 ·
Might want to jump in on the other thread for interest in repop diff flanges with 930CV patterns. Would make for easy axle upgrades.
 
#20 ·
Does it require a special lubricant and what do the manufacturers recommend?

I run the OEM LSD and the(Ford) additive is critical in it's function*****

****

OSG recommends use of their special LSD lubricant, its something like a 75-250 wt, honey like stuff. About $50 a quart, so gear oil changes will not be frequent. I have used the Ford additive too, and Redline's version also. The right amount of "slip" is essential in any clutch disc type of LSD. The tricky thing is getting the comfortable amount of slippage in low speed tight turns, but yet still get full lock at full throttle situations. I have had times where the parking lot turns might be nice and quiet, but full throttle and I fried the friction plates in one autox event because they never fully locked (for me). The OSG seems best to get full lock when needed, and fully unlocked when needed. Most other units, especially all the standard American clutch plate units will be a compromise because its almost all set up with just a preload. Anyway, I am no expert, just working with end results.

Don L.
 
#21 ·
Seen the thread regarding diff flanges. Interesting, but "easy axle upgrades" sounds expensive to me, and I kinda know how long projects like this take to get from drawing board to garage. As I get older, the thoughts of a C6 Z06 that I can drive to an autox event, race, drive home, sound attractive. All with creature comforts, a/c, and 26 mpg. Hmmmmm.
 
#23 ·
As I get older, the thoughts of a C6 Z06 that I can drive to an autox event, race, drive home, sound attractive. All with creature comforts, a/c, and 26 mpg. Hmmmmm.
Pfffft, where's the fun in that :p Come on, you enjoy re-engineering a 30 year old dinosaur to keep up with the off the lot stuff. Its much more interesting to make a slow car fast then it it is to be fast just because you're in a car that was fast to start with.
 
#26 ·
Hi Ken, gosh you have a nice stable of cars! Yes, I agree the OSG stuff is awesome when working correctly. Lots of tuning ability with this LSD units and I certainly have gone the full route with their LSD. I bought the OSG in 2014, part# ty131-HA. Actually listed for an Altezza SXE10 model. I figured the smaller Altezza model has 7.5" ring/pinion, and have heard it would adapt to our cars fine. Indeed, the install was very straight forward, but required some rather extensive adjustments to work for my car, which only recently occurred. I have many friends with OSG diffs in their cars (non-supra), and I cannot find fault with their performance. Maybe just my luck, and perhaps my particular unit might have been off on the tolerances, but works great now.

The guys at OSG know my car, Jon and Sean have had numerous conversations with me. They would take care of whatever questions you might have. Support is great from them, but you may know that already.

Don L.
 
#28 ·
do you still have your kaaz and is it for sale? id love to replace my factory LSD (now welded LSD lol)
with kaaz's ive always used dino oil with amsoil slip additive. some LSDs call for syn. kaaz do not. ive had my tomei (kaaz) in my s13 since 2003, not a daily though. daily'd it for a year or so and has been a "race car" ever since, but has never caused me grief
 
#29 ·
Yes, I still have my Kaaz, but it plays an important back up role in case the OSG diff breaks. The Kaaz has been great, and it took a huge effort to have it modified to a 1.5 way function, which works well for me. I too run dino oil in it, Torco 85-90wt with about 1/2 bottle of Torco Type F friction modifier. Other thing great about Kaaz is I am comfortable moving the clutch plate around to adjust percentage lock up. Tried almost 100%, but now at approx. 70% and is much more quiet in turns. I did not like the Kaaz off the shelf as it is only available as a 2 way, which sucks for my autox hobby. Turns and transitions were terrible, unless lock up was adjusted way down, like 50%, but then total lock up would suffer. Tough having it both ways with 500 hp.

Yup, keeping the Kaaz for now. You should look into Cusco LSD. No experience with them, but if I were to try yet another brand, I would try them just due to their ability to owner change settings.

Nothing wrong with a stock LSD if just for the street. Weir rebuild, then adjust the oil formulation, should be ok too.

Don L.
 
#30 ·
I drift my supra, i used the stock diff, as is, no mods, and it locked terrible (lol its older than i am, of course it doesnt!)
it wouldnt lock at low revs, or near redline when the wheel spin became a lot. i had a narrow window that it would do as its supposed to
so i welded one, to see how it would work. currently "works" (did 1 track day in the rain, no alignment, wasnt great) but ive always had a 2way in my s13 and prefer it...and i feel more comfortable with it than just weld...

kaaz offers 1, 1.5 and 2 way diffs. and now have a "quiet" option as well. I like kaaz because they have a facility if california and there is help and parts in english here. the price for a kaaz has always been a positive as well. and is still mostly current so parts are still readily available.
 
#31 ·
The shop in southern calif for Kaaz provided good support and information to me. When I purchased my Kaaz, maybe around 2010 or 2011, our application only came in 2 way. Not sure about now. 1.5 way is probably best for me, but if I had the time and money, would try a Cusco as it may be available in a 1 way and I really feel for my autox that it might work well. Kaaz was around $1200 back in the day for me. I understand for drifting that a 2 way is best, and maybe even a welded diff. Not in my area of knowledge, but if your stock diff was never rebuilt then I understand why you got the wheelspin and no lockup. A simple Weir rebuild kit would fix much of that. You might even like it because our stock diffs are 2 way, and with more lock in the Weir kit, it approximates a 2 way Kaaz, sort of.

Don L.
 
#32 ·
from what i have seen from weir products and their support, i will never use them, ever.
their rebuild kit might work for the occasional drag person? but i dont see it working for my application.
my stock diffs i have, both look to be what they came from the factory when they were made, and id be lucky if either have had a fluid change, or two, in their lives
 
#34 ·
Ok, well you should buy those products from another manufacturer then... oh wait, nobody else makes that stuff!

I've ordered a weir solid Pinion spacer. Rang them up and ordered it on the phone first try, it arrived a week later, the part was machined perfectly and worked exactly as advertised. I intend to buy as much of their stuff and stockpile it asap in case they ever go out of business, as we have no alternatives. As for the diff rebuild kit, its really hard to tell if the few people I've heard of that had problems with their diffs had the problems due to weir quality issues or if they simply screwed up the install. Diff rebuilding is actually one of the hardest things to get right on cars, and the easiest to screw up. IMO way too many DIYers tackle diff rebuilds themselves. Youtube is not a proper replacement for experience.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top