Yes mine is a stock diff with 30k miles on it.
FTBR 1350M and 5001 combo - Clunk Questions?
- Thread starter BOOOSTD
- Start date
I just installed an Eaton after burning up a Torsen T2R.
If it ends up being the Trak-Lok, will replacing it with another stock Track-Lok remedy the problem? I have a spare diff carrier from the previous diff. pumpkin. I'm really not wanting to spend anything more with this damn car.
Mine is the stock rear, I am most likely going with the Eaton.
How bout just replace the clutches? Im sortof at a loss with the whole "bad carrier" conclusion. You may have some parts that failed in it but it really isnt that common. Youve got the clutches and side gears and the carrier case itself. Not a whole lot to fail.
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So a new symptom started today. When I'm in reverse, there's a constant noise coming from the rear. It's not so much as a grinding or whining noise... its just noise. Also, when I had my car up, I had one wheel on the ground, put a breaker bar between 2 lugs and was able to spin that side relatively easily. When i oscilated from forward to reverse rotation, thats when the clunking sound happened. From what I've read, if the clutch pack is still good, it will take considerable force to be able to rotate just one wheel with the other on the ground. Does this seem like a fried clutch pack to you guys?
It should take 20 lb-ft to twist one side with the other on the ground, which isn't all that much with a breaker bar. I would be looking at a ring and pinion problem with the clunking sound. Also the constant sound when backing up wouldn't involve the clutch packs at all unless you were turning very sharp.
You had the car in gear when checking the differential action?
My car started clunking really bad in all gears including reverse when the joints in the half shafts started going out. You might start looking for play in the drive train. Maybe something prematurely wore out.
A noise is made if I take a sharp turn. Typically a right turn.
I had the e-brake engaged. I could mimic the clunking noise when rotating the drive by hand as well. How would I test to see if the axles are going bad?
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I FOUND THE SOURCE OF MY CLUNK!!!!
I'm embarrassed to post this and can't believe that I missed it over and over but if this post helps someone else out, then I’m good with looking like a knucklehead! That said, I've been chasing this clunk for awhile and it’s finally fixed.
What it ended up being was the front diff bushings were installed incorrectly with the fat bushing/half moon on the top of the diff which was affecting my pinion angle. With my buddy Dave as a second set of hands, we removed everything and loosened up the rear diff mount. I re-installed the bushings correctly (as per FTBR reference pic) and the entire diff raised up substantially. After everything was buttoned up, I noticed right away that the amount of play in my driveshaft (turning by hand) had significantly decreased.
All I can say is WOW, this small change made the biggest difference. The car is a joy to drive and I can now appreciate the FTBR kit. Please do yourself a favour and double check your front diff bushings.
Lastly, I want to give everyone props for their input/support while I figured out this problem!
I'm embarrassed to post this and can't believe that I missed it over and over but if this post helps someone else out, then I’m good with looking like a knucklehead! That said, I've been chasing this clunk for awhile and it’s finally fixed.
What it ended up being was the front diff bushings were installed incorrectly with the fat bushing/half moon on the top of the diff which was affecting my pinion angle. With my buddy Dave as a second set of hands, we removed everything and loosened up the rear diff mount. I re-installed the bushings correctly (as per FTBR reference pic) and the entire diff raised up substantially. After everything was buttoned up, I noticed right away that the amount of play in my driveshaft (turning by hand) had significantly decreased.
All I can say is WOW, this small change made the biggest difference. The car is a joy to drive and I can now appreciate the FTBR kit. Please do yourself a favour and double check your front diff bushings.
Lastly, I want to give everyone props for their input/support while I figured out this problem!
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So it sounds like yours was due to an incorrect pinion angle. I haven't set my pinion angle yet either. So I'm down to 3 things.
1) Possible incorrect pinion angle
2) Center pumpkin needs to be rebuilt
3) Axles have too much slop and are toast
#1 is possible because there could be an incorrect amount of friction with the pinion bearing not allowing for a smooth transition between gears.
#2 is also possible, but that doesn't explain why the rear still clunks at a stand still with my clutch engaged and shifting back and forth between gears...with the clutch still engaged.
#3 I don't think this is the culprit because when I had the e-brake on, the clunk could be mimicked while turn the driveshaft with my hand. The axles didn't rotate at all.
Based on my experience, I wud start with checking your pinion angle and then go from there! Wish you all the best as I know how frustrating and annoying it can be.
Wow! The diff bushings installed wrong?? Son of a!!!!.... Glad you got it figured out!
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I don't know how I missed it, but I did. Nonetheless, it's money now!
Never hurts to double check!
anyone got a pic of what I need to look out for on that pinion angle/front diff mount? I want to double check mine to as I have quite a lot of play in my driveshaft...
Here is a photo of the front diff support. For all IRS applications, you want to raise
the front nose of differential up as high as you can without rubbing anywhere on the subframe.
If you are running our FT 1401 Delrin isolated rear diff lowering mount,
the driveline angles need to be checked once the IRS goes back into the chassis.
Then the shimming washers can be moved to raise or lower the nose
of the differential housing for driveline angle optimization.
From this page:
http://www.fulltiltboogieracing.com/installation.htm
So I got under there again. Found a really embarassing derp. The front diff shims didn't have the same shim count on either aide. I think this ultimately ****ed my pinion bearing and that's what's causing the clunk because the clunk still remains even after fixing it. I'm just going to drive it for a month and trade it in for a C6 vette base or a g37 sport. I'm done with Mustangs...
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And then you'll end up sorting through problems in another performance car platform....
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