4" lift 33" Tires
 

Lifted my jeep 89YJ 4" and put the 33" Cooper SST on. Results is a vibration in 4WD at about 80 KLM/h. Also in 2WD I have no power at approx. 100 KLM/h. I know I have seen the fix in here somewhere. Any ideas how to rectify?

Thanks

Re: 4" lift 33" Tires
 

Are the tires balanced. bad u joint?

Re: 4" lift 33" Tires
 

Thanks for replying to my post. Your the ONLY one that does ha ha. One of the issues is the new angle of the drive shaft. Apparently I can shim that, but I dont think I'll be driving in 4x4 @ 80. The other low power issue could be my ring and pinion gear. I have to figure out what gear is in before I know if I have to change it. I will add a picture of my rig.

Thanks

Re: 4" lift 33" Tires
 

I would bet that gears you have are 3:07's that is what most jeeps with 5spd's came with. Jeeps with 4 banger had 4:10's and auto's mostly had 3:55's. I had lack of power with my, on the highway aswell. But now I have v8 and 4.10's. Rear shaft angle you can rotate rear axle to help that. I reply to most jeep stuff jeep things are like a drug to me.

Re: 4" lift 33" Tires
 

sounds like the perfect power fix......V8. I have to crawl back under and see what I can find. I tried to upload a pic but it says it to BIG. I hate computers..... :)

Re: 4" lift 33" Tires
 

Try "paint" its a program that is usually in Microsoft computors works great I find if any picture is too large using this program and it gets reduced. To the other problem what the H.. are you doing 50pmh in 4 wd? I had the same problem when I did the lift, try changing the steering stabilizer (shock sideway in front), balance tires, how big an angle are your diff's, you might need a SYE? I didn't on the 4" lift but I had a very knowledgeable person doing it for me. Nice to have Good friends.
No power - I have a 6 cy std and with the std 3.07 gears I lost 5th gear, but Now with 4.11 gears its like day and night. This
might help you get ur power back.

Re: 4" lift 33" Tires
 

Thanks on both accounts Mr. White. I am just getting into this jeep thing, so I will NOT be driving in 4wd at 50 again. As far as the gears go. I found a metal plate that says my gears are 3.72. What gears are compatible???? Are they easy to change???. I heard to have to change two sets of gears at the same time. I will try to PAINT some pictures on here later.Thanks again for you posts.

Re: 4" lift 33" Tires
 

if you want to use 4wd you must change front and rear gear sets. not that tough to do.

Re: 4" lift 33" Tires
 

Thats where i'm headed. 4.10:1 gears enough? Im hoping to look at a 4cyl on the weekend with 4:10's How much should they be worth.

Re: 4" lift 33" Tires
 

found a 90 4cyl I have the tag in my hand from the rear diff. It has many numbers but not 4:10. I will check with the dealer tomorrow and my haynes repair book.

Re: 4" lift 33" Tires
 

Hey Patty, (or anyone else) If I get both front and rear axle, would it be easier to swap the axles then change the diff's?

Thanks

Re: 4" lift 33" Tires
 

what are the numbers

Re: 4" lift 33" Tires
 

I would just swap axles thats what I did that way you don't need to set gears up. unless ball joints are shot.I think it was quicker to just swap axles. What motor is in your jeep now ?

Re: 4" lift 33" Tires
 

First the numbers on the rear diff are as best as I can read. As soon as I can confirm they are the 4:11's I will pick them up at the wreckers.



53008521
11605423-1 (tag has been cut off at the -1 and needs to be -11 for the 4:11 gears according to the Dana web site)
-1 is a 3.07 gear. Is that possible in a 90 YJ 4cyl?.....Help

http://www2.dana.com/expertforms/deabill.aspx

The motor is the 4.2l 6cyl. I just tossed the Carter for the Motorcraft and now I need to do a nutter bypass and timing. Its a bit sluggish so i'm hopping that works.

Who comes up with "Nutter"

Re: 4" lift 33" Tires
 

next thing to do is to take cover off and find the numbers stamped on the crown gear. or count teeth and do the math

Re: 4" lift 33" Tires
 

crown gear should have 37 teeth and pinion 9 =4:11

Re: 4" lift 33" Tires
 

So I changed the carb and did a nutter bypass and still no power. Is it all in the gears???. I'll change them but I had my hopes up that the carb and the nutter would give me enough power to enjoy the redults of my labor. Thanks for doing the math for me :)

Re: 4" lift 33" Tires
 

I meant to say in my last post, the motor seems to run fine, good power until I engage the transmission.

Re: 4" lift 33" Tires
 

Before I change everything in my Jeep I could hardly use 5th gear. I have 4in lift and 33's as well.

Re: 4" lift 33" Tires
 

I recently installed the juice box Team Rush upgrade and its running a lot better. The front and rear axles are indeed 4:10 gears so the wreckers are pulling them out today. Install hopefully in the next couple of weeks. Wreckers also has a transfer case and transmission that I thought I would pick up if its the same or better.

I would have to find some numbers on those and look them up before I buy.

Oil leak under the fuel pump ???? i AM READING THAT IT has happened to some jeepers. Picked up the mech pump and will install on the weekend.

This fixing up a jeep is more fun than I had originally thought. Thanks for your help.

CAnt wait to install the gears