Differential rebuild pricing.

[CammyTheCobra]

A shop just quoted me $725 labor, if I supply my own bearing kit, 4:10 gears and clutch pack kit as well as brining in the pumpkin in myself. I have heard from people its generally a few hundred dollars at most for this work. I have worked on cars for over 10 years, oddly never had to rebuild a dif, but ive rebuilt DOHC and SOHC heads and rebuilt motors. I don't have the correct gauges to measure backlash and to my understand IRS is a bit more complicated than rebuilding a SRA. Is this 725 price outrageous? Should I just pick up the tools and do the rebuild myself since I've done more complicated stuff and never shy from a job,usually. I'm not in automotive anymore however even then, I have always shyed away from transmissions and rear-ends for some reason. Thoughts? Should I just pick up the guage and go to town or have that shop or a different shop do it? It's not like ive never done work on a car before.

 

[soccerman002]

That seems to be on the high side - haven't had to have it done, but when I was shopping around for this work I was quoted roughly +/- $500

 

[01yellercobra]

That does seem high since you're dropping the center section. I've seen a write up somewhere about doing gears in these cars. The biggest difference I saw was needing some kind of case spreader for the shims. There was something about needing an extra shim on each side because of how the aluminum case expands. I've never done one myself though.

 

[A_Law]

725 is high. Are your clutch packs bad in the stock differential? If so, might want to invest in a clutchless diff, since your doing a rebuild.

 

[CammyTheCobra]

725 is high. Are your clutch packs bad in the stock differential? If so, might want to invest in a clutchless diff, since your doing a rebuild.

No the clutch pack seems fine from what I can tell. Did the burnout check and the spinning of tires test, both passed. I did not rip the cover off and inspect further. However, I figured if I'm doing gears, I may as well do the clutch packs in the differential as well as all the seals and bearings. The motor has about 10,000 miles, the rear end and body has 113K. So even though the packs are fine, I figured the extra money for peace of mind would be worth it. I'm all for doing it correctly once and not doing it again.

Would you recommend the clutch packs or going with a clutch less differential for durability and performance? Do you have any recommendations for countless differentials or websites?

That does seem high since you're dropping the center section. I've seen a write up somewhere about doing gears in these cars. The biggest difference I saw was needing some kind of case spreader for the shims. There was something about needing an extra shim on each side because of how the aluminum case expands. I've never done one myself though.

Yes, I heard about the case spreader being one of the specified specialty tools among another. Truthfully, if it were a regular solid axle I'd have no qualms about trying this. The IRS unit just seems like it is less forgiving when making installation mistakes. So I decided to not attempt and keep shopping around.

Got a new quote of 425$ with my parts. I'm satisfied with that, so I'll be going through them, they all specialize if Ford products so I'm extremely confident in the future work. They are recommended to me through a facebook group for my area for work.

 

[01yellercobra]

I think the diff is going to depend on what you do with the car. If it's 99% street I'd rebuild the stocker and call it good. I never had an issue with mine, but I don't hit the track that often.

 

[railroad]

You can do it. Be aware of maintaining bearing preload. You do not need a case spreader. Buy Ford gears. I have had good luck with them setting up without changing the shim thickness. You can buy your bearings, if needed from a bearing supplier, much cheaper. Randy's Ring & Pinion has decent prices and can get the stuff to you fast. It seems Ford offered a carbon fiber clutch pack. You might want to look into it, if you go that deep.
Read up on the process of setting up tooth pattern, preload and back lash. You can feel the back lash without a dial indicator, .008 to .010 will work. If you want to see it on the indicator, Harbor freight has the mag base and dial indicator cheap. If you are not 03-04 you might want to consider changing from 28 to 31 spline axles. You will have to change side gears and of course the axles. I am still running 28, just do not axle hop it. Be careful pulling the axles and do not drag them across the seals. Good luck,

 

[CammyTheCobra]

I think the diff is going to depend on what you do with the car. If it's 99% street I'd rebuild the stocker and call it good. I never had an issue with mine, but I don't hit the track that often.

It's going to be a 50/50 in all honesty. I'm in the process of buying the rest of the MM bushings. Found some for a steal, then bought a few others, instead of buying the entire kit from MM. I upgraded to Koni single adjustable struts and shocks, IRS Girdle and Cross member (need bushings for that), before it sees track use I'll be searching for 03/04 half-shafts. So basically yes, it'll be moderately ran on the track, which is why I'm doing this correctly. I'm considering using 03/04 Cobra coupe springs foe the back to add to the drag set-up and keep the front stock since it's a convertible and they're slightly softer (That's a different thread however). So yes, it will be on the track, to the point where I think it will need to be done and done correctly with parts that will take the beating and launches. Sorry, I babbled there, but figured it might be information worth mentioning to answer your question.

You can do it. Be aware of maintaining bearing preload. You do not need a case spreader. Buy Ford gears. I have had good luck with them setting up without changing the shim thickness. You can buy your bearings, if needed from a bearing supplier, much cheaper. Randy's Ring & Pinion has decent prices and can get the stuff to you fast. It seems Ford offered a carbon fiber clutch pack. You might want to look into it, if you go that deep.
Read up on the process of setting up tooth pattern, preload and back lash. You can feel the back lash without a dial indicator, .008 to .010 will work. If you want to see it on the indicator, Harbor freight has the mag base and dial indicator cheap. If you are not 03-04 you might want to consider changing from 28 to 31 spline axles. You will have to change side gears and of course the axles. I am still running 28, just do not axle hop it. Be careful pulling the axles and do not drag them across the seals. Good luck,

I appreciate the added information, I'll be looking it up more. I've got a 31 spline rear the 99's are the only ones that had 28 spline, just a point worth mentioning. I haven't entirely removed the idea of doing it myself I know I'm capable, just need a couple extra tools, the dial indicator being one, which was mostly all I needed besides a case spreader. But you mentioned not needing either. I'll be checking up more information however on this. I have the 4:10's from Ford Racing, I just haven't bought the clutch packs or bearings yet. I've been going back and forth.

I kind of regret not going for the 4:30's after reading up on highway driving and what the RPM's will be cruising on the highway. I'm more worried about sound the gas mileage, this isn't my daily. O/R H going into a 3" Magna packed side exhaust, was more the issue for not going steeper. But we'll see, I don't planning on staying N/A. With that said, I would like to ask, since it will be moderately ran at the track is going with a clutch less dif sturdier or just easier? Does anyone know how different it will be if I went with a different style differential in installation, assuming I do the work myself? Just trying to figure out my vest options before I buy the clutch pack and bearing and seal kit, or just buy an entirely new differential without clutch packs. Some advice would be awesome with what to do next in the differential department would be appreciated. I could just rebuild the clutch packs or swap difs altogether?

 

[RX1Cobra]

I'm considering doing this over the winter myself. I have 4.30 and want to go to 3.55s. Have about 65K miles on mine so I'd be doing a total overhaul too.

 

[CammyTheCobra]

I'm considering doing this over the winter myself. I have 4.30 and want to go to 3.55s. Have about 65K miles on mine so I'd be doing a total overhaul too.

Why are you swapping down to 3:55's?

 

[P49Y-CY]

Got a new quote of 425$ with my parts. I'm satisfied with that, so I'll be going through them, they all specialize if Ford products so I'm extremely confident in the future work. They are recommended to me through a facebook group for my area for work.

that sounds more like it. i had both my diffs rebuilt using new gears, lsd, etc and bringing the unit to them similar to what you are doing. without looking at the reciepts i think that the labor was probably around that much, and that was several years ago

however - i dont think the job would be too hard to do with the right tools. someday i plan on buying the tools and trying it myself. i have always felt buying the tools and saving on labor is better in the long run, plus you have the satisfaction of doing it yourself. best of luck with it!

 

[VA-Mach1]

I did my own with 3:55 to 4:10, all new bearings and fluid of course, and a ford speedometer recalibration tool for about 550. SO 725 for a shop to do it is not that bad.

 

[jeason15]

That's way too much for a bench rebuild, even an IRS. There isn't that much difference between an IRS axle and a solid. They are essentially charging you 10 hours for a bench build @ $75.00 an hour.

 

[CammyTheCobra]

That's way too much for a bench rebuild, even an IRS. There isn't that much difference between an IRS axle and a solid. They are essentially charging you 10 hours for a bench build @ $75.00 an hour.

Hourly rates out here are about $100/hr. Even so, I agree it's absurd pricing for me to bring them the housing and have them do it without taking it out of the ca

I have been looking up tutorials on it, I may end up doing it myself. It seems complicated with the tools required, such as a case spreader, however it really doesn't seem that bad after examining the procedure. I think I overestimated it.

I will probably just do the clutch packs, bearings and gear install, and not purchasesa new differential, yet. I've got the gears, haven't purchased the rebuild parts yet.

 

[RX1Cobra]

Why are you swapping down to 3:55's?

I eaton swapped mine and don't need that much gear now. I drive on the street only so the lower rpms will be nice too.