So since I have my entire rear suspension out, I've decided to go ahead and upgrade my differential along with adding some new gears. I'm thinking about going with an Eaton Truetrac and with some 3.73 gears. My true question is do I need anything else for my build? I'm doing my bushings right now, but I rather leave the work on the differential to a pro. I just need to find someone lol.
Rear end build
- Thread starter Saint
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that sounds like exactly what i did with both my cobras. i am not advanced enough to set up rear end gears, but i can pretty much do all the rest of the wrenching as far as r&r of the whole rear end myself. i assume you are doing a full bushing set while it's apart, right? also i had both my diffs set up with a solid pinion spacer (instead of crush sleeve). has been very helpful when it came time to replace the pinion seal! best of luck with it, and enjoy
Speaking from experience, dont do it yourself if you havent done it before. Setting gear mesh is an art, not a skill. Guys that are good at it have dont it a ton of times. I was able to pull it off, but it took me 4 to 5 times to get it right. It is way cheaper to pay someone to do it.
And those guys that have done it before started somewhere. I ended up pulling my rear end apart to replace the crush sleeve with a spacer. First time I ever did it too. I did a lot of research and took my time. Really the biggest pain was building the spreader for the case. I've put a few thousand miles on it since including some drag racing and it's still doing good.
Setting mesh is no joke. You do you, but it's not easy.
Doing a full bushing install. Working on getting my subframe and control arms powder coated this coming week. Just need to find a rear end specialist to do the gears.
Are you dead set on the true trac? That diff is known to be clunky in its operation. I think that combined with a rear end that is already sensitive/prone to driveline clunk might make for an irritating ride. Would hate to see you get it all done and be unsatisfied.
I've read good stuff and bad stuff about almost every differential. I've been reading for a week into what to get but I'm still open to opinions. What would you recommend?
I didn't say it was easy. Just pointed out that even the pros started somewhere. Setting up mine was my first time too and it worked out. Now I'm not scared to do another one down the road.
What are your goals with the car?
Light drag racing and I've been wanting to get into tracking the car. I'm just meaning to drive the car from time to time.
My 2 cents
I did gears and lash in an bronco I have. A guy I work with and I set it up (who had told me he had done it before). It worked.... For awhile.....
Than the ring gear broke a tooth and got into the spider gears on the carrier and locked my diff up snapping my drive shaft u-joints and on and on..... (While on the freeway)
Just my advice have the pro do gear lash. I learned the hard way $$$ having to buy expensive gears over again and more parts from the failure.
Most everything I will do on a car but I learned setting up gears has to be absolutely precise.
Good luck with it.
Sent from my SM-G965U using the svtperformance.com mobile app
I did gears and lash in an bronco I have. A guy I work with and I set it up (who had told me he had done it before). It worked.... For awhile.....
Than the ring gear broke a tooth and got into the spider gears on the carrier and locked my diff up snapping my drive shaft u-joints and on and on..... (While on the freeway)
Just my advice have the pro do gear lash. I learned the hard way $$$ having to buy expensive gears over again and more parts from the failure.
Most everything I will do on a car but I learned setting up gears has to be absolutely precise.
Good luck with it.
Sent from my SM-G965U using the svtperformance.com mobile app
If it’s likely to be a one time deal, or even two, just pay someone.
I used to be a tech and did it and still hesitated on buying the tools.
But between a CJ5 and the Cobra, it made sense.
Sent from my iPhone using svtperformance.com
I used to be a tech and did it and still hesitated on buying the tools.
But between a CJ5 and the Cobra, it made sense.
Sent from my iPhone using svtperformance.com
I rebuilt the stocker in mine and I use it the same way. Its been working fine for me. Just an option.
On the less expensive end, the ford racing unit. For a better piece, the auburn pro series diff. This is for street/light- moderate drag.
For more emphasis on open tracking, I'd think about a torsen diff and rear end cooler. The t2 for entry level stuff, the t2r for more extreme.
I normally say to always do it yourself, but this is pretty much a one time dealy where returning to the scene of your mistakes is labor intensive and the consequences are high.
Get the Truetrac, 3.73, diffy bearings, solid pinion spacer.
Remove the diffy and take it to a shop, a transmission shop or some place else with competent people, and have them do it.
The truetrac is clunky compared to some of the other much more expensive torque sensing differentials, but it works great and is damn strong.
IMO the truetrac 3:1 ratio is a great street ratio.
The truetrac will not screw up your irs, even an oem irs.
However, you will enjoy the differential more if you were to fix the irs with an FTBR complete kit. Then your only clunk would be the truetrac...and that really is just a bit of back lash.
Get the Truetrac, 3.73, diffy bearings, solid pinion spacer.
Remove the diffy and take it to a shop, a transmission shop or some place else with competent people, and have them do it.
The truetrac is clunky compared to some of the other much more expensive torque sensing differentials, but it works great and is damn strong.
IMO the truetrac 3:1 ratio is a great street ratio.
The truetrac will not screw up your irs, even an oem irs.
However, you will enjoy the differential more if you were to fix the irs with an FTBR complete kit. Then your only clunk would be the truetrac...and that really is just a bit of back lash.
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You can put solid bushings and mounts in the irs and keep things from rocking back and forth, but those solid pieces are going to amplify the clunk of gear backlash that would normally get, at least partially, dampened out by rubber pieces. Add the true trac to the mix and I can only see it getting worse. Some people don't care about that though, and that's ok. I had an 04 irs at one time and the clunk drove me up the wall. Just a natural result of how ford chose to design the irs and mount the differential to the subframe. The less-than-ideal mounting of the diff is also the reason normal driveline vibrations that go unnoticed in sra cars are felt so much in their irs counterparts.
Now I'm debating the Truetrac if it's going to be clunky. I've heard of the Torsen T2 and T2R, but then I've heard of failures with them.
I’m a diy Guy
It’s not hard when following steps
From reading over the years this rear has been hit or miss even with someone who does these.
I paid on first set. Whine city.
I did the next myself after cooking a piñon bearing
It’s not hard when following steps
From reading over the years this rear has been hit or miss even with someone who does these.
I paid on first set. Whine city.
I did the next myself after cooking a piñon bearing
Torsens are great but they ar e not good for hard drag launches, Torsens are better for the track than the trutracks and they are not clunky. About the gearing, 3;73 is the most popular but for me I didnt like, for the street it put my gearing in no mans land---either being to low or high in in 3rd and 4th gear depending on speed. I went back to stock 3:25 gearing when I switched to the torsen but to do over again I would have gone with the 3:55
With your diff out, its a good time to switch to a performance diff cover
There are several available including Ford Performance, I went with this one
LPW 201-8.8IRS: Ultra Rear End Support Cover 1994-2004 Cobra Mustang 1989-95 Super Coupe | JEGS
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