93 850 auto mystery problem

snugani · Post by **snugani** » 27 Mar 2025, 16:20

Hello everyone. For the past several months I've been dealing with a strange issue with my 850. If I go from reverse to drive, especially when backing out of a parking spot the car almost feels like it's catching on something, or something is shifting out of place, and needs a bit more gas to move forward. It makes a very noticeable clunk and then all is normal.

I can Replicate the issue if I shift from r to d a few times when stopped and then try to drive forward. It also happens when I brake and then accelerate when slowing down to make a turn, and recently has even been happening when coming to a stop light. If I take my foot off the brake and let it coast it will barely move until I give it some gas and it clunks.

I've replaced the control arms, sway bar end links, both torque mounts, cv axles, struts, and tried adding the ipd subframe inserts to no avail. This weekend I’ll be replacing the lower passenger motor mount to see if that improves anything. After taking a look it’s pretty crushed, so that may be causing some excess movement. The lower torque mount was replaced with a corteco about a year ago. Im wondering if that could have gone bad as well. I'm really hoping its not the trans, any help is appreciated

snugani · Post by **snugani** » 27 Mar 2025, 16:41

Also, I've done 6 drain and fills on the transmission over the course of 70,000 miles. It does shift smoother but the clunk remains

Post by **scot850** » 27 Mar 2025, 19:23

Check your brake pads. Where you get a lot of rust from salt, the inner pad is held in place by 3 spring clips. These can rust and brake causing clunking.

Check the calipers are not stuck and all the brake pad retaining springs have been refitted.

Check the rear parking brake shoes have not separated and are clunking inside the rear rotors. Also check the parking brake cables move freely.

Check the top and bottom torque rod bushes are good as well as the rear mount on the bulkhead.

The lower right engine pad can brake loose separating the rubber from the metal. Most have a cage to preventing it braking away but will allow movement.

Neil.

Vova585 · Post by **Vova585** » 27 Mar 2025, 19:48

I am no expert in 850 since never had one. I applaud Neil for suggesting usual cool prints for such noise. Another common issue is wear in axle shafts, not torqued axle bolt, wear in the splines between axle and dearing(some early 2000 models were even offered with "antiping" rubber washer). I would find a helper and put front of the car on jackstands so the wheels are elevated.(usual precautions of of using emergency brake, level surface, wheel chocks). Open the hood and ask the helper to start the car. With foot on the brake ask helper to switch into R and then D. Look if the engine has excessive movement(engine pad wear). If you will hear any clicking/clunking you will be able to better assess side since will stay outside. If no abnormal sounds with brakes engaged, ask helper to remove foot of brake and auscultate for adventitious sounds. Hopefully it will show itself.

snugani · Post by **snugani** » 28 Mar 2025, 23:05

Thank you for the replies. As dumb as it sounds I haven't considered the brakes. I will check out the axles and make sure the bolt is torqued as well. I'll post an update if I get this figured out