Hey guys, So i have a 98 on 35's with a 4.5 lift, 4.88 gears. (i bought it with the lift kit) ever since I got it whenever i put it in reverse the xj front end will sag down like a foot as the gear slides into reverse.. is that anything to worry about? it drives fine, i can go 85 on the freeway and wheels just fine. just curious as to why it sags when it is put in reverse lol and do any of you have that too?

 

When you accelerate forward the front end will tend to rise as the pinion tries to climb the ring gear, the opposite is true in reverse. The torque reaction is magnified the lower the axle gear ratio gets. That said, I seriously doubt your front end dives a foot. I would like to see a video of that happening.

 

maybe it seems like it’s sagging way more than it is. But it definitely dips down. Not all the time. Sometimes it just “clunks” into reverse. Half the time it clunks into reverse and half the time it “sags” into reverse. So maybe the pinion is just risen up when I shut the car off. And then when I go out of my driveway in reverse the pinion angle is just dropping. It seems to drop just on the driver side

 

Me too. Even if the drop is half of what you say you have a major malfunction there.

 

I am assuming it is an automatic

I would also like to see a video.

I would also like to know how many rpm the engine is turning at 85mph with 35s and 4:88s. Just out of curiosity

 

I’ll try to get a video of it it today

 

Ill go 65 and rpms are around 2400. Going 85 rpms are at like 3200

 

that isnt bad at all

 

Here is a little vid. Kinda hard to tell but it sagged a little when put in reverse.
let me know if you can see it

 

 

Video didnt work for me

 

Saw it but no help. Need to see from the side.