Trac-Lok Rebuild

[tbone]

How much should a trac-lok rebuild cost?

[MOTOWN]

summit sells the trac-loc rebuild kit(8.8) for $107.95 part# fms-m-4700-c

[tbone]

It's the labor I'm more concerned about. Ford dealer said maybe $350 but his software program ran him in circles and he could not give me definite price. Just like when I went there for the 4.10 install......Ford has problems with quotes.

[tbone]

Thanks for the parts info.

[MOTOWN]

i rebuilt mines my self, its very easy to do if your handy, a couple hours topps!

[tbone]

He was telling me the whole case had to be taken apart again!

[MOTOWN]

from start to finish place rear on jack stands, remove wheels, rear brake rotors, remove speed sensor from back of dust shield, remove rear diff cover, remove center diff pin, remove s spring, push axles in, remove c-clips, pull axles, rotate, and remove top, and bottom spider gears, and washers, remove side splinned spider gears, remove clutches, and steels, install new clutches, and steels in order removed, reinstall side spider gears,axles, and c-clips, top, and bottom spider gear must be rotated in carrier and lined up with center pin holes, reinstall s-spring, center pin shaft, re-install rear diff cover, and refill with gear oil.

it actually sounds more difficult than it realy is

[Shaijack]

i got dizzy reading it does sound easy

[03mmmonroe]

i got dizzy reading it does sound easy

I had two dealers quote me $300 dollars. I am thinking of do then job my self. Hope this helps.

[Blackened300a]

from start to finish place rear on jack stands, remove wheels, rear brake rotors, remove speed sensor from back of dust shield, remove rear diff cover, remove center diff pin, remove s spring, push axles in, remove c-clips, pull axles, rotate, and remove top, and bottom spider gears, and washers, remove side splinned spider gears, remove clutches, and steels, install new clutches, and steels in order removed, reinstall side spider gears,axles, and c-clips, top, and bottom spider gear must be rotated in carrier and lined up with center pin holes, reinstall s-spring, center pin shaft, re-install rear diff cover, and refill with gear oil.

it actually sounds more difficult than it realy is


i got dizzy reading it does sound easy

It does sound easy til you pull your hair out trying to get the spider gears to pop in while preventing the top and bottom shim from sliding out. Then trying to get the "S" spring in is a total mission in itself.
I suggest having a friend handy to help you out.

[MOTOWN]

It does sound easy til you pull your hair out trying to get the spider gears to pop in while preventing the top and bottom shim from sliding out. Then trying to get the "S" spring in is a total mission in itself.
I suggest having a friend handy to help you out.

once you become familiar with the s spring its very easy to install, ive got it down to ten minutes, if you dont know how to install it correctly it can take all day, and still not get it.

[adtaylor]

Are there signs when a track loc needs to be rebuilt, I'm having issues with my rear, thought it was a ujoint issue but was confirmed it's not. And I'm getting a clunking sound when doing real sharp turns, a friend that heard the noise thought that may be my problem with mine.

[MOTOWN]

Are there signs when a track loc needs to be rebuilt, I'm having issues with my rear, thought it was a ujoint issue but was confirmed it's not. And I'm getting a clunking sound when doing real sharp turns, a friend that heard the noise thought that may be my problem with mine.

as the clutches wear they can become sloppy, or loose within the carrier, or in an extreme case break causing the dreaded one-wheel peel!:mad2:

only way to know for certain is open the rear diff, and check it

[Bradley G]

All Data probably calls for .5 -1.0 hours , parts should be a couple hunderd on the high side .

It's the labor I'm more concerned about. Ford dealer said maybe $350 but his software program ran him in circles and he could not give me definite price. Just like when I went there for the 4.10 install......Ford has problems with quotes.

[thathotrodlincn]

Some people (me included) like to presoak the friction elements in gear oil prior to assembly.
Good luck. Let us know it goes.

[TFB]

I installed the FMS kit in the 8.8" in my T-Bird, first(and only)one I've did, wasn't a big deal... If you start the "S" spring in long ways and then lightly tap it around into position it's a breeze, took maybe five minutes to get it lined up correctly...

[LeoVampire]

Just do not forget to put friction modifier in with the fluid once you put it together or you will be doing it all over again in short order.

[tbone]

Just do not forget to put friction modifier in with the fluid once you put it together or you will be doing it all over again in short order.

The synthetic oil doesn't need a seperate modifier.

[tbone]

as the clutches wear they can become sloppy, or loose within the carrier, or in an extreme case break causing the dreaded one-wheel peel!:mad2:

only way to know for certain is open the rear diff, and check it

That's what happened to me at the track. I have it on video. The burnout was ok just previous. I could see the driver's side wheel spin. Could it be that the passenger wheel was still a little wet? I had rubber on the fenders on both sides, but the passenger side was quite a bit more.

[MOTOWN]

That's what happened to me at the track. I have it on video. The burnout was ok just previous. I could see the driver's side wheel spin. Could it be that the passenger wheel was still a little wet? I had rubber on the fenders on both sides, but the passenger side was quite a bit more.

on a posi rear the passenger side will always get most of the traction, thats why you see cars pulling to the right on launch, when you open up your diff you will prolly find worn clutches, just replace em, maybe even go with carbon fiber rebuild kit which can withstand more torque (which is what was used in the cobra)

[tbone]

So maybe my diff is ok?

[MOTOWN]

So maybe my diff is ok?

launch it on pavment if you get two black lines, and no noise, and or clunking during cornering its fine, if you should fail this mission, your rear diff is in need of new clutches!


good luck tbone:beer:

[tbone]

No clunking during cornering.

I don't do burnouts other than the ONE track day I went to since I waited 9 months for these BFG rear tires. Since they are now pretty worn already, in the middle of course, I think I will toast them and see the results of the even rubber test.

I'm still not sold on other tire options since I think all of the competing tread patterns are rather funky. Some may be better tires, but fugly imho.

[MOTOWN]

hell bud! bfgs are the worst imho! you have far better choices out there, may as well explore as you will have no choice in the near future!

[tbone]

I love the look of the tire. But beauty is only skin deep.

[ctrlraven]

I have a cobra clutch pak and s-spring for sale. (FMS-M-4700-C) $105 shipped. I bought it a while back and just ended up buying a new diff instead of rebuilding my stock one.

[RF Overlord]

The synthetic oil doesn't need a seperate modifier.Actually, that depends.

Motorcraft 75W-140 synthetic does need a bottle of FM. Some brands that do NOT need it are: Valvoline, Pennzoil, and Royal Purple. There are prolly others, but I know those for sure.

Just look for either the words "limited slip", a black square with the white letters "LS" on the label or see if it says on the back that it's suitable for complete fill (as opposed to top-off) of a limited-slip axle.

[ctrlraven]

Actually, that depends.

Motorcraft 75W-140 synthetic does need a bottle of FM. Some brands that do NOT need it are: Valvoline, Pennzoil, and Royal Purple. There are prolly others, but I know those for sure.

Just look for either the words "limited slip", a black square with the white letters "LS" on the label or see if it says on the back that it's suitable for complete fill (as opposed to top-off) of a limited-slip axle.
Actually Valvoline does for our application, when I bought some I had the Napa guy double check and he got a Valvoline rep on the phone and they said it does have SOME FM in it but highly recommend adding in Ford's 4oz bottle of FM as well.

[fastblackmerc]

Actually, that depends.

Motorcraft 75W-140 synthetic does need a bottle of FM. Some brands that do NOT need it are: Valvoline, Pennzoil, and Royal Purple. There are prolly others, but I know those for sure.

Just look for either the words "limited slip", a black square with the white letters "LS" on the label or see if it says on the back that it's suitable for complete fill (as opposed to top-off) of a limited-slip axle.

75w140 Redline doesn't need any additives.

[ctrlraven]

How do your spider gears look? (if you know)

When I would of had to rebuild mine I would of had to replace the spider gears as well along with the cobra clutch pak. That's why I just bought a new FRPP 28-spline diff since it was only $180 and I would of spent that much in parts and labor to have mine rebuilt. I just had to get the master install kit since the new diff needed new bearings and cones pressed on.

[Bradley G]

Yeah, I'm thinkin' complete overhaul; axles, Bearings, seals, deffinately new shafts,splines and new spiders! you know "The Works" ! :P


How do your spider gears look? (if you know)

When I would of had to rebuild mine I would of had to replace the spider gears as well along with the cobra clutch pak. That's why I just bought a new FRPP 28-spline diff since it was only $180 and I would of spent that much in parts and labor to have mine rebuilt. I just had to get the master install kit since the new diff needed new bearings and cones pressed on.

[Chevyguy]

There is a torque spec for the Trac Lock. Dunno the factory value, but while the car is in park use a torque wrench on one of the rear wheel studs and measure the torque needed to turn the wheel. This reads the amount of friction applied by the differential. When the clutch packs are worn you will get about no torque measured.

[justbob]

I'll do it for $200.00 :)

[tbone]

I'll do it for $200.00 :)

When the time comes, ok. :) But I want to see for sure if it needs it.

[yjmud]

after what I saw at the track I say yes

[justbob]

A "justbob" brake stand should answer that in 20 seconds or less.:D

[tbone]

after what I saw at the track I say yes

No soup for you!

[Chevyguy]

The Carbon fiber clutches are a upgrade from the stock clutches

http://www.summitracing.com/parts/FMS-M-4700-C/

[Bradley G]

When mine was going south, it occasionally would leave two marks but the slipping only got worse and eventually, I was being hammered at the stop & Go lights by a Prius

[Mercguy04]

Ford Racing M-4204-F318C - Ford Racing Traction-Lok Differentials

[ctrlraven]

Ford Racing M-4204-F318C - Ford Racing Traction-Lok Differentials
28-Spline FRPP
http://www.latemodelrestoration.com/item/M4204F288/Mustang-88-28-Spline-Traction-lok-Differential

31-Spline FRPP W/cobra clutch pak
http://www.latemodelrestoration.com/item/M4204F318C/Mustang-88-31-Spline-Traction-Lok-Differential-With-Carbon-Fiber-Clutch-Disks

[tbone]

I punched it out of the carwash today and left 2 black marks for 100 ft. down the street. Maybe my trac-lok is ok.

[justbob]

I think I soiled Zacks pants today as we hit 130 MPH in about 6 feet LOL...

[tbone]

Bob, can you drive my car on Sunday and give me your opinion?

[ctrlraven]

I punched it out of the carwash today and left 2 black marks for 100 ft. down the street. Maybe my trac-lok is ok.
When was the last time you changed the diff fluid? lol

[justbob]

Bob, can you drive my car on Sunday and give me your opinion?
Sure? But there really is only two ways to tell... Smoke show NOT water assisted and bad noise/rubbing sounds on turns (normally what was good clutches and someone forgot to add FM.)

If your car ever did a one wheel peel, then it is on the way out. Might wanna keep it easy till your ready.

[tbone]

Ok, well the point is null and void. The smoke show WAS water assisted at the track and I was told my trak-loc was worn out because of what someone saw. I guess he was wrong. No noise or anything else. It's been perfect.

[guspech750]

Bob, can you drive my car on Sunday and give me your opinion?



I called shotgun!!
Too bad sooooo sad Tom:)

Sent from my iPhone
Go White Sox!!!

I remember hearing chattering and just a rough sound going around turns before I had my clutch pack replaced.

[Bradley G]

If it's not broke it will be after testing :D

[yjmud]

a rebuild is always a good thing

[tbone]

I remember hearing chattering and just a rough sound before I had my clutch pack replaced.

Are you talking about your car or last Saturday night?:confused:

[tbone]

a rebuild is always a good thing

Not for 300+ samolians if it isn't broken.

[ctrlraven]

I had a one wheel peel off and on for a year or so. Sometimes both tires would light right up and sometimes just the right one.

If you haven't changed the fluid try that first since it's the least expensive thing ($60 for 3 quarts of RP or Motorcraft - plus 4oz FM for Motorcraft only). Valvoline or Mobil 1 75w-140 "LS" are around $12-16 per quart and just swing by your local FLM dealer and buy some friction modifier to throw in.

[tbone]

I had a one wheel peel off and on for a year or so. Sometimes both tires would light right up and sometimes just the right one.

If you haven't changed the fluid try that first since it's the least expensive thing ($60 for 3 quarts of RP or Motorcraft - plus 4oz FM for Motorcraft only). Valvoline or Mobil 1 75w-140 "LS" are around $12-16 per quart and just swing by your local FLM dealer and buy some friction modifier to throw in.

I put in the Mobil 1 LS when I went to 4.10 gears. No additional modifier. You really think I need it?

[justbob]

I add FM no matter the product used. When mine went south at 40ish thousand miles there was NO warning, just a 3/4 track one wheel burnout :) Go lay a good patch Tom, the car begs for it anywho! Your probably fine.

[tbone]

Did the dry burnout. No issues.

[Bradley G]

The track has a way of promoting the peg leg action.
If one tire is still wet or not gripping equally for any reason, the wheel that spins easiest wants to keep spining.

[ctrlraven]

I put in the Mobil 1 LS when I went to 4.10 gears. No additional modifier. You really think I need it?


I add FM no matter the product used. Went mine went south at 40ish thousand miles there was NO warning, just a 3/4 track one wheel burnout :) Go lay a good patch Tom, the car begs for it anywho! Your probably fine.
It can't hurt to add the FM to whatever fluid you use. RP and Redline usually have enough in it because they specialize in high performance stuff where as other brands may have enough for just normal daily driving.

[tbone]

Now that I thought about it, I gave the Ford tech the Mobil 1 LS and a bottle of friction modifier to put in. I'm sure he did it.

This whole thread was for nothing.:shake:

[justbob]

can we get a YOU FAIL here please?

[tbone]

Makes for good conversation if nothing else.

[justbob]

Boobies are funner to talk about... Just sayin.