Installed FTBR diff bushings now loud clunking...WTF???

[xtremekustomz]

I Just got my car all tightened up. I installed the front diff bushings from FTBR to lift the front of the diff all the way up like explained in the video and also installed a FR Diff cover for reinforcement and swapped out the the IRS bushings on the frame for MM Ureatane bushings and put the proper bolts back in.... Now I drive the car and I can hear what sounds like tranny noise, and everytime I let off hard from the gas it sounds like the diff is hitting the tranny hard...WTF? It never did that with the stock bushings and rubbers on the diff. All i can think off is the shimming all the way up on the diff has caused the driveshaft to move back and forth..Any other suggestions on why the load banging noises and gear noises???????

 

[ac427cobra]

I Just got my car all tightened up. I installed the front diff bushings from FTBR to lift the front of the diff all the way up like explained in the video and also installed a FR Diff cover for reinforcement and swapped out the the IRS bushings on the frame for MM Ureatane bushings and put the proper bolts back in.... Now I drive the car and I can hear what sounds like tranny noise, and everytime I let off hard from the gas it sounds like the diff is hitting the tranny hard...WTF? It never did that with the stock bushings and rubbers on the diff. All i can think off is the shimming all the way up on the diff has caused the driveshaft to move back and forth..Any other suggestions on why the load banging noises and gear noises???????

The first thing you need to do it to make sure you didn't leave any fasteners loose during the installation.

You always had a clunk in your drivetrain before the installation of this kit, you just did not hear it as well as you're hearing it now.

As the FAQ on our site states:

FTBR FAQ's


A: There are a few reasons for this. Your transmission, differential and halfshafts can all combine for quite a bit of play, but that usually is not the MAIN source of the "clunk".


Depending on how many miles are on your car you may need to go through the diff and possibly the trans as well. Or take the easy way out and dynamat the floorpan:

FTBR FAQ's

Most of the people that have had this issue either left something loose or need a diff rebuild.

Keep me posted with what you find. We are here for support.

:thumbsup: :coolman::beer:

 

[xtremekustomz]

Thanks for the response, but I checked everything and its all tight, Is it possible by lifting the diff all the way up that I have effected the driveline angle too much and now the banging is the driveshaft moving back and forth?? I cant belive that suddenly since I changed these things now that i have driveline issues.

 

[ac427cobra]

Thanks for the response, but I checked everything and its all tight, Is it possible by lifting the diff all the way up that I have effected the driveline angle too much and now the banging is the driveshaft moving back and forth?? I cant belive that suddenly since I changed these things now that i have driveline issues.

No you did not affect the driveline angle too much. Do you have one single shimming washer on top of the small bushing and corresponding covnex washer on the front diff mounts? If not your diff housing may be contacting the main tube on the subframe which would be adding to your noise.

But as previously stated, you had this noise before, you're just hearing it much better now. I'd get some dynamatting and remove your rear seat and put that down on the floorpan right above the diff housing.

How many miles on the car, what kind of gears, how long have the gears been in there?

 

[xtremekustomz]

42,000kms (26,000miles) Original 3.55. Put new Royal purple diff fluid after changing diff cover gears where clean and tight. Ill have to look at it again, but i really can understand how it now sounds like the driveshaft is slamming my transmission after changing those small things listed above.

 

[xtremekustomz]

Bye the way i am not trying to trash your product, just looking for a solution.

 

[ac427cobra]

42,000kms (26,000miles) Original 3.55. Put new Royal purple diff fluid after changing diff cover gears where clean and tight. Ill have to look at it again, but i really can understand how it now sounds like the driveshaft is slamming my transmission after changing those small things listed above.

Not sure what you mean by the driveshaft slamming the trans? If you unbolted your driveshaft from the diff I guarantee you you can push it at LEAST a half an inch into the trans, probably twice that. Also, remember the diff does not move in an IRS.

 

[xtremekustomz]

Heres my install pics.

I dont know how to explain it. Say you press the gas and then lift your foot while the cars in gear, it makes a hard banging noise on de acceleration in gear. Never did that before install.

 

[ac427cobra]

Heres my install pics.

I dont know how to explain it. Say you press the gas and then lift your foot while the cars in gear, it makes a hard banging noise on de acceleration in gear. Never did that before install.

Ok, let me make sure I have this clear. In your OP I don't see any reference to you replacing the rear diff mounts. Perhaps you simply forgot to mention that:

I Just got my car all tightened up. I installed the front diff bushings from FTBR to lift the front of the diff all the way up like explained in the video and also installed a FR Diff cover for reinforcement and swapped out the the IRS bushings on the frame for MM Ureatane bushings and put the proper bolts back in.... Now I drive the car and I can hear what sounds like tranny noise, and everytime I let off hard from the gas it sounds like the diff is hitting the tranny hard...WTF? It never did that with the stock bushings and rubbers on the diff. All i can think off is the shimming all the way up on the diff has caused the driveshaft to move back and forth..Any other suggestions on why the load banging noises and gear noises???????

Now when you installed the Ford Racing diff cover did you read the installation instructions regarding possible interference between the Ford Racing diff cover and the OEM rear diff support bracket? Here is the wording included in the installation instructions that came with your kit:


If you are putting the OEM rear diff support bracket onto the new Ford Racing rear diff cover, you’re going to want to check for interference with this combination of parts. The steel portion of the bracket may contact the cover. This needs to be ground or belt sanded. For more information regarding this see the installation photos and tips page on our web site. You can test fit the rear support bracket onto the rear cover of the differential to see where it needs to be relieved. Make sure you have a minimum of 1/8” of clearance.

That will certainly cause additional and unecessary noise.

There is more information regarding that on our installation photos and tips page as well:

Installation Photos and Tips

 

[xtremekustomz]

Yes it is OEM rear bushing. I only bought the front bushings from you guys and the diff cover from someone else. I check when I installed it for any issues but did not notice anything touching. I will have to look under it again tommarrow and see if i can see it rubbing any where. Is there an easy way to remove that bushing to see if it is rubbing?

 

[ac427cobra]

Yes it is OEM rear bushing. I only bought the front bushings from you guys and the diff cover from someone else. I check when I installed it for any issues but did not notice anything touching. I will have to look under it again tommarrow and see if i can see it rubbing any where. Is there an easy way to remove that bushing to see if it is rubbing?

Well I am pretty sure that is your clunking issue. Those rear diff bushings are total weak sauce. And if you've read the FAQ on our website we do NOT recommend stabilizing only one end of the diff housing:

FTBR FAQ's

"Q: "I was going to buy one of your rear differential mounts and was wondering if using a urethane front diff mount will have a negative effect?"
A: Your plan for the diff mounts is a bad one. You never want to have the rear of the differential housing stabilized with our mount and try to have the front stabilized with that lousy poly. You'd run the risk of cracking the rear cover with that combination. No different than replacing the front with aluminum and leaving the rear rubber or poly. That would run the risk of cracking the front mounting ears. Always replace the front and rear differential mounts at the same time stabilizing both ends of the differential housing."

You will have to have someone load your drivetrain in forward AND reverse, with the service brake applied while you take a peek under the car and watch for the differential housing moving. It should NOT be moving AT ALL. If it is moving that is your clunk!

The rear diff mount bushings require the removal of the differential housing from the subframe.

Check that out and report back with your findings.

 

[xtremekustomz]

Awsome ill check it in the morning. Thanks for your help It looks like i may have to order the rear bushings from you guys.