MONTE CARLO Bad axle hop after ls1 swap

[Haley72692]

Recently finished my Ls1 swap in my 1988 Monte Carlo and under wide open throttle it’s either axle hopping or trying to throw the driveshaft out of it. Car is lowered 4” in front and 3” in rear so wondering if pinion angle has been affected and the car also still has stock control arms with stock bushings in them which I’m sure isn’t helping. Wondering what would be my best course of action to fix this? Aftermarket rear control arms with adjustable uppers to get the pinion angle dialed in? If so what’re you guys running

 

[L92 OLDS]

Recently finished my Ls1 swap in my 1988 Monte Carlo and under wide open throttle it’s either axle hopping or trying to throw the driveshaft out of it. Car is lowered 4” in front and 3” in rear so wondering if pinion angle has been affected and the car also still has stock control arms with stock bushings in them which I’m sure isn’t helping. Wondering what would be my best course of action to fix this? Aftermarket rear control arms with adjustable uppers to get the pinion angle dialed in? If so what’re you guys running

I think you answered your question. I used the cheap harbor freight angle meter below to verify pinion angle after my LS swap. Your stock control arms are not helping either. A good set with roto joints will help to prevent wind up and wheel hop. Check out UMI's selection. You only need roto joints on one end.

https://www.harborfreight.com/dial-gauge-angle-finder-34214.html

 

[81cutlass]

I fought this recently. Put a posi in and it started hopping.

Changed shocks, didnt help
Boxed stock lowers, didnt help
Put adjustable uppers in, dialed in pinion angle, didnt help
Changed lower control arm bushings with energy susp. poly, fixed.

If you are cheap and can do it at home (a bench vise worked for me), and have a welder, spend $12 on material and weld them solid, put some $60 bushings in and it fixed it.

If you dont have a welder or the time, get at least a set of boxed lowers with better bushings, address the uppers if you feel inclined.

 

[pontiacgp]

I fought this recently. Put a posi in and it started hopping.

Changed shocks, didnt help
Boxed stock lowers, didnt help
Put adjustable uppers in, dialed in pinion angle, didnt help
Changed lower control arm bushings with energy susp. poly, fixed.

If you are cheap and can do it at home (a bench vise worked for me), and have a welder, spend $12 on material and weld them solid, put some $60 bushings in and it fixed it.

If you dont have a welder or the time, get at least a set of boxed lowers with better bushings, address the uppers if you feel inclined.

I got the solution to your problem, put in a stock 3.8 and I guarantee your problem with wheel hopping will disappear .......

 

[565bbchevy]

With your lowered ride height and stock rear control arms your pinion angle is definitely off, some adjustable uppers will fix that.

 

[Haley72692]

Bought some adjustable uppers and lowers with poly bushings, will update thread once I get them and get em on

 

[Michael Watts]

Your control arms are binding. I would take it easy until you get it fixed,

 

[pontiacgp]

With the stock old bushings there is probably movement causing the wheel hop. The new Mustangs are known for wheel hop caused by the movement in the control arm bushings.

 

[Haley72692]

Got the control arms in and went to install the mini spool and it doesn’t fit, the center section is way to small with the axles and clips pulled all the way out, assuming I got sent the wrong one but have no way to tell because it was drop shipped from jegs in an unmarked box, how do I know what one I need?? Any help would be great as I need to have the car drivable by Saturday morning

 

[pontiacgp]

what is the brand and part number of the mini spool they sent you?