Hey guys I have a 9 inch rear axle but its took long for my truck, I called a guy to see how much it would cost to shorten it and he said about 300. I was kind of wanting a posi unit installed buts like 500 bucks so I guess I don't needit as bad as I thought LOL. But I was looking at my axle yesterday and one axle was wider than the other like the pumpkin was offset and I'm thinking I could possibly get one axle cut down and resplinded for half maybe 150. What you guys think?

I recently got a Lincoln town car for a donor but the rear axle is a 8.8 and seems to have a lot of play in it like a wheel will turn about 3 inches before catching (one side of car jacked up). Its also a 28 spline compared to my 31 spine axle 9" but the Lincoln will fit without any cutting

 

I would do the lincoln rear or wait and get a pre 72 ford truck 9" I paid $150 drum to drum for mine. Posi units run about $350-$500 If you have a 31slpine 9" pumkin it will fetch a few more $$ The 28 spline if fairly strong and plentiful, unless you're rockcrawling or racing it...

The lincoln may have a traction device in it causing the perceived "play"...

A lot of this is about budget and what you want.. do you want/need bragging rights to say you have a cut down 9" 31 spline axle? That's not meant to sound rude but, I know it's a selling point to folks... Lastly believe a pre 72 can be fitted with a 31 spline setup.

bob

 

I actually tried a brake burnout with the lincoln and it only spun one tire. I thought it was a posi traction and spin 2 wheels. I was a little disapointed when I found that the 8.8 wasn't a posi because I had read alot of material that said that those lincolns came with posi units but my lincoln is a base model so I guess it didnt come with it. I just figured that if I could get the 9 inch axle cut down it would be stronger for later on if and when I get my engine rebuilt with some mods so it will handle the power. Its just an open axle

 

Something else thats keeping me from the lincoln 8.8 is that it only has a 3.08 gearing with the 302/AOD combo in it. The 9" has 3.50 gearing and I figured it would be a better gear for my truck with that same 302/AOD combo

 

agreed, I think the AOD has like a .6?OD so you may even go higher. ?The LSD may be worn out on the lincoln.

OK knowing that I still suggest looking for an empty pre72 housing or cutting yours down. Do you need it now? Is there something else that needs to be done prior to the rear. I know I was obsessed with the rear for weeks now it's just sitting on my bench. I and I may not even put it in?

Do you need a new rear? What's in there now? research what the final drive ratio on the AOD is and go here:

Speed / RPM Visual Calc

I have a 4.27 and I may just use an overdrive tranny I have here with 0.70:1 final drive ratio. and save the rear until later on. My current rear is in great shape new brakes and only 77K on it.

 

One other point, I would not be afraid to run that 302 in the high 2K's or 3000rpm. I have a flathead so I need to keep a lower rpm. If I put a 302/351 I would base 65mph at a around 3K. My views have changed over the years, sometimes I feel we ( vehicle enthusiasts ) are to concerned about low cruising rpm's. so your engine may not last 150K miles but who cares ya might not be allow to own a gas engine in a few years...

 

Reed, if you are using a AOD, I wouldn't change the stock (3.92 or 4.11 ?) rear until you've tried it with the AOD. That is a pretty steep cruising combo, 2.75 or 2.88 @ .70 O/D ratio.

 

My stock rear axle has 3.92 gearing, but would it be able to handle the 302?

 

absolutely, it's a dana 44(41). unless you're doing something crazy with it? you can easily update the brakes using later ford brake parts like auto adjusters and spring kit.

 

Bob,

I think one reason the pumpkin is offset to one side is to keep the u-joints in motion. If you cut down one side and center the pumpkin the only motion they will get is up and down as you go over bumps. I think you need the motion to keep the grease flowing inside the u-joints.

By the way, I got my '71 9 inch from pick n pull on half price day for 35 bucks. No drums, so I had to buy those new.

 

As long as the pinion angle is not at 0 deg. the U joints will be OK. Lots of cars and trucks have the engine offset to one side so the pumpkin will also be offset by the same amount. Correct setup is critical but not hard. There are lots of good articles and websites that have some good info on this subject.

http://www.clubfte.com/users/jniolon...nephasing.html

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