TCCoA Forums banner

1 - 18 of 18 Posts
Joined
·
622 Posts
Discussion Starter #1
where is the best place to get a set of 3.73 gears? I just purchased a 3.27 TL diff and am wanting to change to 3.73s. I have searched and looks like I will be spending $160+ after shipping for FRPP. Any where cheaper? or other gears that are cheaper, but decent quality?

seth

oh yeah, while I'm here. What all is involved in removing the rear differential? I found a non-thunderbird specific guide and it mentioned removing/loosening rear sway bar and dissassembling brakes and stuff. Is that all necessary? I have searched here and can't find any information. thanks
 

·
Premium Member
Joined
·
5,862 Posts
where is the best place to get a set of 3.73 gears? I just purchased a 3.27 TL diff and am wanting to change to 3.73s. I have searched and looks like I will be spending $160+ after shipping for FRPP. Any where cheaper? or other gears that are cheaper, but decent quality?

seth

oh yeah, while I'm here. What all is involved in removing the rear differential? I found a non-thunderbird specific guide and it mentioned removing/loosening rear sway bar and dissassembling brakes and stuff. Is that all necessary? I have searched here and can't find any information. thanks
$160 for a 3.73 TL diff is an EXCELLENT price and good deal. Things to look for are that the splines are 28 spline (our 'Bird axles), not the 31 spline (which is common in the Explorers). Also that the gears are machined for the IRS (beveled, so you can pry the axles out to remove them and the snap ring will pop out). All late model 8.8 28 splines are machined for IRS, but the older ones are not, I don't remember the cut-off year.
 

·
Registered
Joined
·
2,542 Posts
3.90's

Hello

I paid more for my 3.90's. Motive Gear.
I don't run a TL, rule thing!

I got 3.73's for a 7.5 in a auto 80's pony
I got 4.10's for a 7.5 from a 90's mini van.

:xpD:
 
Joined
·
622 Posts
Discussion Starter #5
so, there is no need to open the differential to remove the snap rings to remove the halfshafts? I found some good instructions after more search, but just want to be clear about that, because I have found some conflicting information elsewhere that is not t-bird specific.

thanks,
seth
 

·
Registered
Joined
·
892 Posts
so, there is no need to open the differential to remove the snap rings to remove the halfshafts? I found some good instructions after more search, but just want to be clear about that, because I have found some conflicting information elsewhere that is not t-bird specific.

thanks,
seth
The axles just pop out. I just put a 373 together for my sons Mark VIII. I think he paid like $156 for FRPP gears.

Brad
 

·
Registered
Joined
·
1,998 Posts
Check Ebay. I got a fantastic deal on my gear. Sometimes you have to be in the right place at the right time.

Don't get Motive, they are made in China and I hear they are noisy. Doing a gear is something you want to do only once due to $$$$
 

·
Registered
Joined
·
2,542 Posts
Don't get Motive, they are made in China and I hear they are noisy.
My car is sooo! loud I can't hear them. So I can't say they are noisy.

I had to go to someone that had 3.90's for a 8.8. Ford did not!

Been running them for 4 seasons so far. Make sure they are in correctly.
You shouldn't have problems.

:wiggle:
 

·
Registered
Joined
·
892 Posts
My car is sooo! loud I can't hear them. So I can't say they are noisy.

I had to go to someone that had 3.90's for a 8.8. Ford did not!

Been running them for 4 seasons so far. Make sure they are in correctly.
You shouldn't have problems.

:wiggle:
I had 3.91's in my 340 Duster years ago and for an auto I thought they were perfect in the 1/4. I had pigs with 4.10 and I think 4.56 but I was way high rpm coming through the traps even with the 4.10. Used to pop the 4.56 in for the parking lot drags wintertime at Michigan Truck (Ford pickup plant). '72 I was consistently beating a 429 Hemi Mustang (he was really a bad driver). We raced 700'. Lots of fun and "lots" of money even by todays standards.

Brad
 

·
Premium Member
Joined
·
9,165 Posts
Seth, I got my 3.73's from Ebay... just be careful who you buy them from. All you really need is the gears themselves, (the ring and pinion). The pumpkin you bought already has the Trac-loc in it. (some of the posts sounded confused on that point)

Buy a set of 3.73's and the two diff rebuild kits.. (one is for reassembling the pumpkin and the other for the trac-loc itself, including new clutches). then take all the parts and kits to a reputable rebuilder and have him put them together.

LOL almost felt sorry for the guy that did mine. I showed up with a VERY worn out 3.27 trac-loc pumpkin, the two rebuild kits, the 3.73 ring and pinion, and an aluminum Mark VIII case and said "i want the parts out of the old case, rebuilt and assembled in the aluminum case, with the 3.73 gears, using an F-150 "S" spring"... LOL fortunately he a good ol' small town guy who knows what he is doing. When he was finished I picked up a brand new rebuilt 3.73 TL in an aluminum case, and a box full of old, worn out, and VERY stinky dif parts.

But I digress....

To remove the rear end, just loosen the rear spindles from the control arms giving them room to move.. then remove the driveshaft bolts. Pry the shafts from the diff with a big screwdriver, (they should just "pop" out) then put a jack under the diff and remove the bolts holding it in place... lower carefully and roll the jack out.

Oh yea, you'll ned to remove the exhaust to.
If you want any help, just let me know and I'll see if I can manage a trip over to springfield.
 
Joined
·
622 Posts
Discussion Starter #11
Thanks traveler. I think i can manage. You're welcome to come anytime, but it sounds like you have alot going on. Have you already gotten moved?
I already have my transmission being worked on. I have a 93 mkviii drive shaft waiting to go in. I have the differential that I need rebuilt/regeared. I am ready to get it all back together and drive my car again.

Seth
Thanks for the reassurance of the rear differential removal.
 

·
PostSlut
Joined
·
13,597 Posts
The first one - do you need all the bearings?
the second - do you really want the carbon cluthes? the regulars work really good.
and the third...I believe that is still a motive gear set...hence the M on the part number.(yes, it does have a ford part number, but the gear is motive).
 

·
Premium Member
Joined
·
9,165 Posts
I used an "S" spring for the F-150.
 
Joined
·
622 Posts
Discussion Starter #15
The first one - do you need all the bearings?
I don't know. I was going to get the whole diff rebuilt while I had it out as was suggested by Traveler. Should I just get the basic kit instead of the deluxe?

the second - do you really want the carbon cluthes? the regulars work really good.
it was the first thing I saw. I didn't know there were others. I have since found them. (M-4700B)

and the third...I believe that is still a motive gear set...hence the M on the part number.(yes, it does have a ford part number, but the gear is motive).

anybody else know if this is correct. The gears listed on fordracing.com begin with an M. (M-4209-F373N). If that is not the FRPP gears. Where can I get them?

Thanks.
Seth
 

·
PostSlut
Joined
·
13,597 Posts
1) It just depends, if you had the time to open the case and inspect the bearinngs. If not, there is nothing wrong with the delux kit.

2) yep, m-4700B

3) I hope I did not scare you about the gear.....it was just what I ran across when searching for gears a couple years ago.(I could be totally wrong...as I really have nothing to back my claim)
 
1 - 18 of 18 Posts
Top