Just got a call from the shop...the 4.10's are howling when it coasts down. He also said it sounds like there is some grinding noises and sometimes "like a boat sinking." He said it didn't sound good...they have installed them before on Automatics and have never seen this apparently. He thinks it might be a ring and pinion issue.

Any tips on what it could be?


One more question,..can I keep my 93 Octane tune with the DiabloPredator when they recalibrate the speedo?

 

I don't think that standard vs. automatic should make a difference here. It's the installation that is a problem. They need to check the clearances & backlash and use the shims if necessary. A good install will also check the gear tooth pattern using some white grease.

I haven't upgraded my rear gears yet due to poor installations in my previous '94 GT vert. I had three different shops (last one was a Ford dealer) try to get my 3.55s right but they never got it as quiet as the 2.73 stock gears back then.

Don't accept the job if it sounds as bad as you describe! Just my opinion.

 

The 4.10 gears they installed is the ring and pinion. I would have responded, "no sh$# sherlock".

"They" don't recalibrate the speedo, you do it yourself with the Predator. Reinstall your 93 tune but "modify parameters" to change your gear ratio to 4.10.

 

Noisy gears like that will eventually fail and potentially cause BIGGER issues besides the $170 gears. I'd make them redo it AND buy you a new set of gears.

 

I agree with both dustindu4 and pjdami. Especially since you're using frpp gears, they should be able to get them as quiet as the stock gears.

 

The guy said he is going to redo the entire thing and work on it until it's done right. I haven't picked up the car yet because they refused to let me drive it with that sound. I get the feeling they are committed I just hope it all works out.

This shop is famous and has loads of cars on the cover of all the top magazines...why is this such a problem?

 

The coast side gear contact pattern was set incorrect.
The marked teeth check will answer everything, and once you see that you will know whether to shift the pinion in or out, or decrease backlash.
(They apparently cut corners, and that's unacceptable)

 

Have them install new 4.30's!!

 

If the guy from the shop says he'll redo them, then heck, why even call the customer and tell them the dreaded sounds and problems he's having. Just fix it. On a side note, how much does it cost a FORD dealership to install since they are FRPP's.

 

I talked to my dealership about installing the gears and heck even told them that I would be willing to buy them there. $345 for the gears and $545 to install. Some of these dealerships are just plain crazy. I'm going to have West Coast Differentials install my gears because that's all they do and they carry FRPP gears on the shelf.

 

They MAY NOT be actual Ford gears. I would check the stampings to make sure. Someone I know, received their FRPP 3.73's and guess what....they're Motive's and cheap one's at that.

 

I've asked my mechanic who specializes in Mustangs and he told me a few weeks back that it all depends on the manufacturer of the gears. He told me that it's a proven that Ford Racing gears fit better than, for say, Richmond. Due to the fact that Ford Racing gears are specially made for Ford vehicles which means a perfect fit and would not require any shims.

 

Rumor has it that Richmond makes the FRPP gears from 4.30 on up.

 

#1 I think you made about half of this up.
#2 I don't think you even know that Ford 4:10 gears are made in Italy and they are not Richmand but are made in the same factory that makes motion gears. If it looks exactly like a motion gear but stamped Ford what would you call it?

#3 All installations require shims. The rear end housing manufacturer has machine tolerances in order for the rear end to except the machine tolerances of the gears so shims are required to mate the gears properly. A dial indicator is also required to install.

Nick if a shop tells me they are going to make them right I would appreciate this and not get all worked up over it. Have a beer or two and relax.

 

What a flamin' retard. Get your facts straight before you flame someone's mechanical knowledge and personal opinion.

 

I don't know about the 1st 2, but after pinion preload is set, you can begin the ring instalation, and shims are required to fine tune a proper pattern and backlash. The dial indicator is what is used to measure the backlash.

 

I would have to agree with mongoose on this one.
One small thing it's Motive gears not Motion.

 

freakin AMEN to that

most fun, EVAR

 

I did and just smoked a joint