Questions on 8.8 swap and other related information

Joe K

Member
Joined
Sep 24, 2021
Messages
37
Location
Florida
Hey guys.

So ill try to make a long story short. My dad bought this jeep about a year ago maybe more.
4139E1F3-656D-4026-B6A3-971BF9060B92.jpeg

Since hes owned it ive been working on it and i made a post here on his behalf.

It was all over the road. Had heim joint steering linkage. Sloppy control arms. Junk steering box.

Since then and through learning about jeeps i have replaced the steering box, installed currie correctlync, and metalcloak control arms all the way around. (I did the front axle bushings too 😎)

So now the jeep drives straight! My dad was on the verge of “driving it to the junkyard” for a while. He was just getting frustrated.

Now i believe the only issue we have is a vibration under acceleration.

The jeep has a ford 8.8 rear axle.

The jeep just got aligned yesterday and the axles are straight to eachother and centered on the frame.

Can you guys tell me what we have for a driveshaft and if this is an SYE?
20F92CB8-200F-4F80-AA08-578C301BF4AD.jpeg


I do not know a lot about driveshafts but i have read that with these lifted TJs you want a sye and a cv driveshaft.

Does this look like a good hearty setup?

Is there anywhere else i should look for the cause of this vibration?

Thank you guys!!

Joe
 
I don’t know the 8.8 that well, but that is a Double Cardan drive shaft.

Just to be 100% sure, I would check by pulling the rear DS and drive in 4H, are the vibes gone? If so, then it’s your rear for sure, which it seems to be.

Do you have adjustable rear control arms? You need to then check the pinion and drive shaft angles to the rear of the TC. Needs to be right at it, or 1/2 degree below to account for acceleration pushin up slightly.
 
Thanks,

I can do that. Im sure there are resources here on how to check that angle… i will have to take a look.

Is the double cardan driveshaft something that you like? Or would you rather see a cv driveshaft there?

Thanks

Joe
 
Hey buddy!!

Thanks for the help.

I adjusted the rear lower control arms shorter by 4 turns and all my issues are gone.

Thanks again

Joe
 
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Thanks,

I can do that. Im sure there are resources here on how to check that angle… i will have to take a look.

Is the double cardan driveshaft something that you like? Or would you rather see a cv driveshaft there?

Thanks

Joe
Many call that a CV driveshaft but it is more correctly called a DC driveshaft. Can you post another photo from the side that shows the rear axle's pumpkin all the way up to the DC joint? It'd be good to see the axle's pinion angle, maybe it's too high or too low which will cause vibrations.
 
One of the problems with an 8.8 swap
In a TJ is they introduce a compound driveshaft angle. Good news is you have the right parts there to help dial it out. Based on your pic it looks like you should try and raise the pinion a touch and see if things improve.
 
Yes sir thanks jerry and blackjack.

I shortened up the lower control arms which rotated the pinion up and i have no more vibrations.

You guys are great and thank you for the quick answers!!!

Joe