Rear-end

[MJTShowdown]

Hey everyone. I've been going throughout my mustang and now its time to do my rear end. I have a 1966 with a stock open dif and the lame highway gears.

My question is what is the most cost efficient way i can go about getting new gears (preferably 3.73s), posi traction and (maybe) rear discs. I looked on randys ring and pinion and they seem to be quite expensive for 3rd member setups.

From anyone whos done this before, what do you suggest?

EDIT:

I now have a new 3rd member for an 8 inch rear end. i've been trying to break apart the center section so that i can start the process. Do i need to slide the axles out in order to replace the 3rd member? I have all 10 bolts off the casing but it will not split.

Any suggestions appreciated.

 

[Mike65]

When I built a 68 GT coupe back in the 80's I did the top end of the engine & wabnted more pop off the line I went from the stock 2.80 rear to a 3.50 & made a world of difference & just stayed with the regular non posi rear.

 

[mustangls1]

some guys use the leaf spring rear out of ford explorers.supposed to bolt into your perches.

 

[ponyboy289]

Hey,
How have you been? The project is looking good. I'm curious as to what you were looking at on randy's and what type of number they were looking to get? That will help give me a baseline. My thoughts are figuring what rear you want to go with. Currently you have an 8". So you could stay with that(In my experience typically 8" performance stuff is scarcer ,more expensive,and you have less offerings than for a 9 inch)? Go with a 9 ", you have to find,buy,etc. and swap The whole setup from drum to drum (or disc to disc)? Or try the explorer swap?
I've never done the explorer swap ,but I've heard the pinion angle is off and you have to cut and reweld the spring perches, I think there were a couple of other mods that need to be done as well. Disc brake rears are cool, Are you looking to road race the car? Rear disc can be done,but they cost money and may be overkill for your setup?
I'm a fan of good brakes what about discs in the front and larger rear Drums? That's How Carroll Shelby set them up. I think Mike65 has a list for adding larger drums using cheaper Crown vic parts? You should post it mike.

As far as ratios I know you're doing the t5 swap so you could go deep in the gears. A few weeks back I saw an ad in Mamaroneck for a guy selling a freshly setup 8 inch posi center with 4.11 gears I think he was asking $450,it's not cheap but it's definately very reasonable. I told a friend about it ,I don't know if he bought it or not?

Myself, I like posi's I have 8 and 9 inch setups in cars.I've been fortunate to piece stuff together over the years.As far as Disc brake rears,I had a versailles setup in a car at one point it was reasonable price wise,because I got lucky and found a deal,but the parking brake was a hassle and I never ended getting that sorted out.Ultimately I sold that rear and I went to a 9 inch setup with big drums in the back (ala shelby) ,I believe I pirated the drums off of a Fairlane station wagon.Nowadays you can get good rear disc conversion kits,but like anything else they're not giving them away,which leads me back to beginning what are your project goals/needs, Intended use for the car,and most importantly budget.

 

[MJTShowdown]

please check original post

 

[ponyboy289]

Hey Mark,
Yes, you absolutely need to pull the axles before the center can come out. To do this remove the rear drums and undo the four nuts then the axles may slide out,If not the most helpful tool for this is a slide hammer.You can borrow these from the large chain auto stores.You can also try a method with a wheel or a brake drum,flip the drum around and place it over the lugs,install three or more lug nuts,loosely and yank on the drum,this sometimes works. I own a puller so I don't often resort to this although it has served me well in junkyards a few times over the years. Next the center,after 40 plus years they often like to stay put so,you may (probably will ) have to gently bang a chisel or large screwdriver between the pumpkin and the carrier.Good luck. I'm off to respond to your suspension post and your P/M....

 

[MJTShowdown]

so i have the new center section attached, with the old one removed. The only problem im running into now is that my driveshaft is not aligning with the new center section, even though they appear to be the same length. Any ideas? The driveshaft appears to be about an inch (or less) away from where it would attach in the new center section.

 

[ponyboy289]

so i have the new center section attached, with the old one removed. The only problem im running into now is that my driveshaft is not aligning with the new center section, even though they appear to be the same length. Any ideas? The driveshaft appears to be about an inch (or less) away from where it would attach in the new center section.

Hey Mark,
Hmmm, I'm trying to picture this? So in theory are you saying it's as if your current shaft is too short? If yes there is slack in driveshaft front yokes,pull the driveshaft back towards the rear of the car and see if it reaches and bolts to the pinion flange? Please get back to me and let me know if I have addressed the problem you are having? Sonetimes it's really hard to figure stuff out when you're looking through a keyboard.LOL .You know the saying a picture is worth a thousand words,sometimes,more sometimes less.

BTW Did you get me respose to your P/M? If I didn't say it in there We could work something out and you could absolutely work along with me. Plus I do make housecalls.

The old saying with car s and such is never throw anything away(within reason) .You should put your old rear center section aside as a just in case.

 

[MJTShowdown]

The center section is aside, but i'm hoping i dont have to go back to it. Here are some pictures for reference. Let me know what you think after seeing them.

 

[ponyboy289]

Hey Mark,
Those pictures are not very clear,sadly.That said,Have you tried to pull the driveshaft back? When you do this does the driveshaft fall out of the trans? Front yokes have extra length on them ,they have this because as the car goes over bumps,etc. Technically the distance between the trans and the rear end changes.I have another question how is the car supported? If the body is lifted and the suspension is in a fully extended postition it is at it's longest position.BTW Did you measure the depth of the new center vs the depth of the original?

 

[MJTShowdown]

We did measure the depths of the centers, and they appear to be the exact same. We have the car lifted on ramps and jack stands, but also realized that the suspension would be fully extended. We decided to also jack up the rear end to its normal ride height, but to no avail. The driveshaft would still not hook up.

I have not tried pulling on the drive shaft, as i do not have much room to work, but figure its worth a shot. I'll give it a go next time i am under the car.

Sorry about the quality of pictures. Not much room in my garage and they were the best we could get.

 

[ponyboy289]

Mark,if the centers have the same depth and this shaft was hooked up before the rear swap.The front yoke of your driveshaft is just too deep into the transmission.Just wiggle it and pull it back and you should be in business.Good luck

 

[shmoo]

i'll chime in here, there are a few different styles of Yoke that comes on these 3rd members.

measure the length of your old yoke. you may have to swap over the old yoke onto the new 3rd member, but keep in mind you need to setup the bearing preload on the pinion when you do it. you can't just unscrew the nut pop off the yoke replace it and then re-tighten the nut, it has to be set with the correct bearing tension using a dial indicator and possibly re-shimmed, and you will have to do this with the 3rd member back off the car and on the bench. you may have to adjust the backlash between the ring and pinion if something changes in the spacing when switching yokes.

I work on the 9" which is a little different then the 8".

first measure the length of the old yoke on the 3rd member, and compare it to the new one.

 

[MJTShowdown]

Rear end is all done. Loving the 410s