Rear End Gear Swapping August 02, 2009, 08:02:53 PM I have two rear ends. One is a 1987 2.73 traction lock year out of an 87 sport. The other is a 3.08 "one legger" rear out of an 88 base model tbird. Both of them are 7.5' rears with drum brakes. Can the gears from the 3.08 be put into the 2.73 housing to make it a 3.08 traction lock rear?I don't care about having the drum brakes. Ive already taken the v8 motor out of the 87 and the transmission and put it into the 88, and now I would like the tractio lock rear, but don't want to go down to the 2.73 rear. Is this possible? Do I need to get anything in addition to make it work?Thanks. Quote Selected
Rear End Gear Swapping Reply #1 – August 03, 2009, 04:20:46 PM Yep, swap the whole gear set and trac-loc over to the other carrier. Its pretty straight forward but you should use a dial indicator for measuring backlash when setting up the new gears. A press is also pretty handy. Here is the process I used on my 8.8. A 7.5 should be almost identical.http://www.corral.net/tech/drivetrain/gears.html Quote Selected
Rear End Gear Swapping Reply #2 – August 05, 2009, 02:08:31 PM NO!!!!!!!!. Just swap the carrier from the 2:73 rear to the 3:08Remove the carrier and ring gear from both rear ends. Remove the 2:73 ring gear from the trak lok carrier using an impact gun (be careful the ring gear teeth are sharp and will cut you to shreds). Now remove the open diff from the 3:08 ring gear and install the 3:08 ring gear on the trak-lok carrier. Reinstall using the same shims that came out of it in the same orientation. Now purchase friction modifier from the Ford Dealer cost about $11 and comes in a small bottle other wise that rear will wine going around corners. Don't worry about having quad shocks either. I don't run them and have no wheel hop and if they do it's an excuse to have CHE control arms. Quote Selected
Rear End Gear Swapping Reply #3 – August 05, 2009, 02:17:47 PM I suppose that would work too. I would still check your backlash or at minimum your contact pattern because the two center sections won't be identical. Quote Selected
Rear End Gear Swapping Reply #4 – August 05, 2009, 04:45:10 PM Quote from: danzajax;285402I suppose that would work too. I would still check your backlash or at minimum your contact pattern because the two center sections won't be identical.X2 I agree. Some pattern marking compound should be used just to make sure. Use red loctite on the carrier boltsIf your going to go through the trouble of changing the gear themselves hold off and get some 3:45's = (cheap). You will feel no difference from a 2:73 to a 3:08 just too close together ratio wise to make a difference. Quote Selected
Rear End Gear Swapping Reply #5 – August 05, 2009, 05:23:46 PM Whoa whoa whoa,swapping gears is not for the faint of heart or backyard inexperienced mechanic here.You must take careful measurements in pinion preload,backlash and contact pattern otherwise you will ruining your rear end.You can swap the 3.08 ring gear onto your trac loc center section then remove your pinion gear and install the 3.08 one(you cannot mix and match pinions they are a matched set) but they then must be setup as i described above.I also highly doubt you will be able to get the correct pinion preload torque if not on a hoist as it requires over 200+ft lbs of torque from a 4-5 ft bar.If you have never done a rear gear setup(this is an advanced repair)then i would not touch it and take it to someone who has experience.I am a licenced tech by trade and have done several rear ends,i still don't like doing them and always second guess myself even though i have never had one come back.Usually takes between 4-5hrs for a correct swap and setup including new bearings.My advice: leave it be unless you want to be out a car. Quote Selected
Rear End Gear Swapping Reply #6 – August 05, 2009, 05:44:03 PM I agree with dominator. If your interested I have a 7.5 345 track lock. been trying to unload for a while. I built it it's solid. 100 plus truck freight. Less than a 1000 miles on it. Quote Selected
Rear End Gear Swapping Reply #7 – August 06, 2009, 05:58:43 AM Change the track lok carriers between rear ends on your own it's not a big deal and your not messing with the pinion depth. Besides I have never bought a 7.5 rear end. They were always given to me because there in the way and no one wants them. Gain some experience and change out the carriers. I've done it this way on multiple cars and no whine or damage. You do need specialized tools and knowledge if doing a complete gear swap though. Quote Selected
Rear End Gear Swapping Reply #8 – August 06, 2009, 07:09:10 AM How do you figure,sure your not changing the depth or the or pinion pre load but you will still be changing the contact pattern if not adjusted side to side correctly.It sounds as though he does not have the special tools or much knowledge on the subject as to the reason why he is asking.I just don't want the guy to cause major damage to his rear end. Quote Selected
Rear End Gear Swapping Reply #9 – August 06, 2009, 02:04:57 PM Use marking compound to test the pattern if it has the right contact pattern your golden if not you have to play with the shim sets a little. Only special tool required is a torque wrench Quote Selected
Topic: Rear End Gear Swapping (Read 1096 times)
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