Mustang Evolution Forum banner

2002 GT 3.73 Rear

3K views 21 replies 6 participants last post by  WAR HORSE 
#1 ·
My car was purchased with an aftermarket set of gears. The 3.73s have made noise since the day I bought the car. It only roars when the rear end is under a load. There is no noise at all when the car is coasting. The sound of silence in that situation is beautiful.

I am about to pull the drive shaft in order to repair a leaking tail shaft seal on the poor old TR3650. While the shaft is out, and while I am under the car, what do I need to look at concerning the rear end?

Treat me like a baby, take me by the hand, and give me the step by step instructions on what to look for and what to do.

The clutches are good inside the rear (I had to make sure before new tires were installed). Both tires break free and spin as they should. There are no wierd noises when I turn, so I think the planetary is good. The fluid is also full.

I have listened to the roar long enough. Help.
 
#2 ·
I am not an expert or very experienced with this. But since no one has replied yet I thought I would try to help. I'm dealing with some rear end issues myself right now so I have been reading up and will share with you what I have found out. When you disconnect your driveshaft check to see if the flange that is mounted to the rear end has any slop in it at all. There is a bearing on the other side of that flange that wears out and creates noise. There is also the potential for the gears not being lined up or tightened correctly when it was originally installed. Since you mentioned they were installed aftermarket gears and that it only makes noise under load if I am remembering what I read correctly that would be gear noise not bearing noise. Hopefully others will chime in to help more.


Sent from my iPhone using Mustang Evolution
 
#3 ·
According to what I have read I have to agree with you. I believe it may be gear noise.

When I spoke to the previous owner he was aware of the noise. When the shop installed the gears they told him to expect some noise. They went as far as to tell him 3.73 gears were noisy.

The previous owner knew little, or nothing about cars. Everything was done at the cheapest shop he could find. I have spent a year slowly repairing and replacing other people's mistakes.

When I was a kid my dad installed a set of 4.10 gears in my Chevelle. It never made a sound. I have a Dodge Dakota R/T that had a new set of gears installed, and they were quiet as well.

I am far from an expert, and I am not interested in pulling the rear end apart, but funds are always tight on my end. I just paid to have a transmission installed in my wife's Grand Cherokee. I chose the guarantee of a well known shop over my own abilities.
 
#10 ·
the rear wasnt set up right , there are shims on the pinion gear that have to be correct , some times it takes several times to get it right , adding a shim then checking how deep the gears are meshing with paint , if the shim thickness isnt correct rear will whine or sing as they say
 
#12 ·
Can I check and adjust what I need to without pulling the rear calipers, axles, and other components?

I will already have the drive shaft out to change the tail seal on the trans.

I am contemplating removing the factory mufflers and replacing them with 2.25" pipe, or checking my uncle's old racing parts for a set of Cherry Bombs (glasspacks). I need more noise to cover the present noise. Lol
 
#17 ·
IT sounds worse than it is, on American Muscles web site they have step by step instructions with pictures for a gear swap , I used it when I did mine , I started with the same size shim that was on old pinion gear , had to add 2 more but 1 at a time so that means I installed the rear 3 times, thats the worse part , maybe you will be lucky & get the proper gear mesh the first time
 
#20 ·
on the pinion gear there is a bearing , behind the bearing is the adjustment shims , you cant see them or it until the bearing is removed, there are shims on each side of the ring gear also but dont think they are the problem , that shim controls how close the gears are together , add shims in .002 increments , press the bearing on , install in housing & put marking paint on ring gear to check gear mesh,there are pix on AM web site that shows how it should look , if its not right you gotta take it out & add another shim , may take several tries, its a pain for sure , maybe you'll be lucky & only need 1 shim , if you add too many to start with you'll be taking them back out so add 1 at a time
 
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