'86 w/3800sc and Beretta 5spd, Between acceleration and deceleration it feels like there is a loose spot like slop in the drivetrain. I have felt this on other cars even with automatics. It also has another feel to it that I can't quite put my finger on, It's like the cradle is turning maybe, like one wheel is pulling ahead of the other although the car does keep going straight. It just feels like something is moving and shouldn't be. It has the original axles and CV joints I assume, original cradle bushings and no dogbone. Any one have any ideas or noticed this before? I just want this car to feel tight. Most everything else is new using Moog parts.
Something *is* loose. It's just a matter of figuring out what. No dog bone could be part of it. Engine, tranny mounts. Cradle mounts. Any suspension bolts/bushings. Loose axle bolts.
Once you've verified everything is solid, then I'd look at alignment settings. Be careful doing just a visual inspection. I've seen mounts separate where they looked perfect at rest, but under load the rubber and metal had completely separated. If you have a mix of solid/rubber/poly mounts, that can cause the weakest link to fail more rapidly. You should use all the same type mounts for best reliability.
I'd start with an alignment and go from there. Heck, they might even find what's at fault while doing the alignment. My 87 had bad inner tie rod ends in the back when I bought it that made the rear end shift around when accelerating or decelerating. If nothing else, put in a dog bone mount.
[This message has been edited by fastblack (edited 07-07-2014).]
No dogbone...yet Motor mounts are PR's mounts and new Tranny mounts are Rodney's and new Just had an alignment Suspension parts are new which include, tow rods all tie rod ends all control arm bushings all ball joints upper and lower Sensa trak shocks and struts steering rack steering dampener
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Originally posted by phonedawgz:
Have you tried shifting between forward and reverse while holding the brake and having someone watch to see which rear wheel(s) is moving?
No, they should both move unless one spins?
When shifting, there just feels like a lot of slop there too. If you are not careful shifting, it can bang around like slop in the transmission maybe?
No dogbone...yet Motor mounts are PR's mounts and new Tranny mounts are Rodney's and new Just had an alignment Suspension parts are new which include, tow rods all tie rod ends all control arm bushings all ball joints upper and lower Sensa trak shocks and struts steering rack steering dampener
No, they should both move unless one spins?
When shifting, there just feels like a lot of slop there too. If you are not careful shifting, it can bang around like slop in the transmission maybe?
Steve
You didn't mention the cradle bolts. Make sure they are tight. Loose bolts will give the symptoms you describe. If they were loose when you got your alignment, you'll need to get it done again.
I have an 86 GT and it's doing the same thing and it's getting more noticable. When I accelerate the car yaws a bit to the left and when I decelerate I can feel it yaw back to the right. I also noticed my right rear tire is worn more on the outer edge than the left rear. I'm off the next few days and the car will go into drydock over the weekend and have the rear tires replaced. I suspect a worn bushing somewhere or something is loose. About 4 years ago I put in a 3.4 and had the cradel done over and replaced the rear struts. I put in all new poly bushings on the cradel and had the car aligned. I'll let you know what I find out.
Check your Axle Nuts for proper torque! I say again - Check Your Axle Nuts for Proper Torque! I have seen loose axle nuts cause the ass end to be "loose" under acceleration and deceleration!
Last Thursday I jacked up the back end and checked it out. Everything appeared tight. I didn't remember but when I put it all together 5 years ago I had replaced all the rear control arm bushings with poly ones. I replaced my rear tires and scheduled an alignment at Sears for the next day. Turns out the right front upper control arm had a worn out bushing. The back end of the control arm could move about a 1/4 inch. When I took off the control arm the top rear bushing just fell out. It was worn all the way thru on the inside. I also had a bad left wheel bearing. I have been neglecting the front end since I replaced the front struts back in 2006. While I have the front end torn apart I'm replacing the ball joints, tie rod ends, bushings, bearings, shocks, and rotors. Some time back in 2000 when I first got the car I did a front brake upgrade and put Beretta rotors and calipers on. I was always a bit skeptical about my brother-in-law's machine work. Now I have my own lathe and I'll do the machining myself. When it's finished the steering should feel tight again instead of like a Walmart shopping cart.
