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Fitting a Ford 9" for my car.

3K views 36 replies 9 participants last post by  SSedan64 
#1 ·
I have an 1986 Olds cutlass and for those of you who have read my other threads the stock rear end came apart on me. Well my machinist said he would show me how to do a 9" conversion. He said he has done it for many cars. Would this bracket kit work?

http://cgi.ebay.com/ebaymotors/9-Fo...dZViewItemQQcategoryZ33731QQitemZ390203898288

He made it seem rather easy. He said we put the car up on the lift and let the rearend hang down and then measure where it sits and then put the 9" in the same place make sure the pinion angle is right and weld the brackets in place after hooking up shocks and control arms. Thanks for any help.
 
#6 ·
What they said ^^^ :D no Hangman. Post above was just about the Mount Kit.
Many raise the UCA mount position higher than stock position to move the Instant Center location for better launch. Similar to what the No Hop Bars do but, this way it doesn't create a binding situation when the axle articulates. The UCA mounts in the Kit are cut to fit so it's easy to do. There are LCA mounts with multiple mounting holes to lower the LCA's to change Instant Center also.
 
#7 ·
big gear head said:
I wouldn't let the rear end hang down and weld the brackets on. I would have the rear end at ride height and weld the brackets on. I've never seen anyone do it with the rear end hanging down. Too much can change when you raise the rear end back into position at ride height.
Alright that makes sense. I must have heard him wrong.
 
#8 ·
THe bracket set looks right and about the same thing I used when I did the 9" for my 83 El Camino, which is the same G Body platform as you're Olds. Here's the thread I put together when I did it.

http://www.elcaminocentral.com/showthread.php?t=28724

The big thing will be finding a 9" that is narrow enough (57-9 Ford Stations wagon or Bronco).

By the time you go thru a JY rear end you may find it's not as cheap as you think it will be.
 
#9 ·
THe bracket set looks right and about the same thing I used when I did the 9" for my 83 El Camino, which is the same G Body platform as you're Olds. Here's the thread I put together when I did it.

http://www.elcaminocentral.com/showthread.php?t=28724

The big thing will be finding a 9" that is narrow enough (57-9 Ford Stations wagon or Bronco).

By the time you go thru a JY rear end you may find it's not as cheap as you think it will be. You will also need to replace the drive shaft to make this work.
 
#13 ·
quick question. I am leaning more towards the ford 8.8 now. my local u pull has one out of a lincoln with a modular motor. He said its posi and should have a 3.55 gear in it but i will go through it and make sure hes right. Will the bracket kit from the 9" work with a 8.8" rearend? Thanks
 
#15 ·
zildjian4life218 said:
quick question. I am leaning more towards the ford 8.8 now. my local u pull has one out of a lincoln with a modular motor. He said its posi and should have a 3.55 gear in it but i will go through it and make sure hes right. Will the bracket kit from the 9" work with a 8.8" rearend? Thanks
The outer arm brackets will work, but how are you going to weld the upper arm brackets on?? It is a cast center housing.

Maybe the Lincoln has cast ears for upper arms, and in a usable position and usable angle?? I'm not familiar with them.
 
#18 · (Edited)
big gear head said:
There are a lot of people using the fox Mustang 8.8 in the G body cars. They claim that all you have to do is use the correct upper arms and weld on a set of spring perches.
ok this is the info i have found so far. The best donor will be a 95 and up explorer. They had 31 spline axles some came with limited slip and most had decent gear ratios. Of course I will check the carrier and gear ratio but there are a ton of these at the local u pull. They also came with disc brakes. I also found the stock gm 7.5" width to be 57.5" and the explorer was very close to that. I would only need to take a couple inches off each side of the housing. anyone have any truth or better suggestions to what i have said? Thanks

This is a good write up http://www.theturboforums.com/smf/index.php?topic=104354.0
 
#19 ·
offset pinion

I have a question thats revelent to the thread if you don't mind ZJ4L. With the nine inch pinion being offset, is one axle tube and axle shorter/longer to center the pinion in the frame or did all the fords run drive lines that were off center to the frame? One tube shorter/equal axle length? Not being familiar with it just got me wondering.olnolan
 
#20 ·
OLNOLAN said:
I have a question thats revelent to the thread if you don't mind ZJ4L. With the nine inch pinion being offset, is one axle tube and axle shorter/longer to center the pinion in the frame or did all the fords run drive lines that were off center to the frame? One tube shorter/equal axle length? Not being familiar with it just got me wondering.olnolan
There were a few with a centered pumpkin, '72-76 Torino/Cougar/Montego comes to mind, along with the small '77-79 Crown Vic/Lincoln Versailles(the Granada platform one). Most everything else was offset.

Someone else might know of some others.

Pretty much going to come from cars that have a factory 4-link rear and the upper arms attached to the pumpkin. Mid 70's LTD/Thunderbird is 4-link, but seems like all the arms attach to the axle tubes(like the 71-73 Vega does) and nothing to the pumpkin so it doesn't need to be centered.
 
#21 ·
OLNOLAN said:
I have a question thats revelent to the thread if you don't mind ZJ4L. With the nine inch pinion being offset, is one axle tube and axle shorter/longer to center the pinion in the frame or did all the fords run drive lines that were off center to the frame? One tube shorter/equal axle length? Not being familiar with it just got me wondering.olnolan
Exactly what eric said. some were offset some were not.
 
#23 ·
Engine is almost always centered from what I know, driveshaft runs down the tunnel on an angle to get to the offset pinion flange. Can't tell you on the tube lengths and axle lengths.

Even GM stuff with equal length axles(10 bolt, 12-bolt) have a pinion offset to the passenger side, engine centered, and the driveshaft goes down the tunnel on an angle. GM offset the BBC engine to the passenger side in '67-69 Camaro and '68-70 Nova, but that was just so the exhaust manifold would clear the steering box, not to match the rear axle.

I don't know of a single car that has an absolutely centered pinion gear so that the driveshaft is straight from the trans to the pinion flange, the driveshafts are all angled the amount the pinion is off centerline of the rear case. The driveshaft is never perfectly parallel to the engine centerline as it heads to the rear.

A lot of people seem to mistakenly think the driveshaft runs through the car/truck exactly parallel with the frame rails... it never does in any car I've ever seen.
 
#25 ·
OLNOLAN said:
Maybe I'm missing something cause I always thought the GM pinions were centered like in this photo;http://www.google.com/imgres?imgurl...ndsp=18&ved=1t:429,r:15,s:28&biw=1276&bih=575
While it looks centered in a photo like that, it isn't. It is about 3/4-7/8" to the passenger side. Fools a lot of people because it looks centered to the naked eye, so they assume it is. It you take a tape measure and measure from each backing plate to the pinion center you'll see what I mean.
 
#26 ·
pinion centerline

Thanks for the tip Eric, To the naked eye it looks centered. I guess less than an inch of offset over the length of the driveshaft will still operate smoothly? I guess you can tell I've never done alot of driveline setups from scratch, mostly just worked with what was there.
Still curious about the nine inch tube/axle lengths. Nolan
 
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