reverse slam

Hello to all.

Just bought a 1999 LeSabre with 76k miles last week. Love it so far.
Had a question though...when it's cold (outside and engine) and I shift to reverse, it really hits hard. I'm concerned that damage will be done to other driveline parts, as well as that there may be some problem with the transmission. Does anyone have any insight on this?

Also, the fuel pump seems very noisy and does not cycle off when the key is in the run position.

Thank you kindly to all who respond.

Well from personel experience the reverse slam is a good indication that the tranny is weak...Better to leave that diagnosis for the moderators... You could just need a tranny flush and filter as for the feul pump?

I'd start by checking the fluid level. Does the fluid smell burnt? Then do a fluid/filter change and pour in a bottle of auto-rx.
www.auto-rx.com

The trans fluid looks good, nice and red, normal odor, level is good, also.

A few questions that need to be answered before we can begin to diagnose.

1) Do you have a tachometer in the instrument cluster and if so what is the engine RPM when you shift to reverse?


2) When you first shift to reverse, does the “hit hard” happen immediately thereafter, or is there a delay before this happens?


3) A further explanation of what you mean by “hit hard” may help! I assume you have your foot on the brake and if so, does the engine move or lift from the rear mounts. You may need someone to assist watching the engine when shifting to reverse!

Hello to all.

Just bought a 1999 LeSabre with 76k miles last week. Love it so far.
Had a question though...when it's cold (outside and engine) and I shift to reverse, it really hits hard. I'm concerned that damage will be done to other driveline parts, as well as that there may be some problem with the transmission. Does anyone have any insight on this?

Also, the fuel pump seems very noisy and does not cycle off when the key is in the run position.

Thank you kindly to all who respond.

What does the transmission do when you shift into 1st or D with the same cold engine before you shift to R?

What does the transmission do when you shift into 1st or D with the same cold engine before you shift to R? Thanks imidazol97 for another good question! :cheers:

1. Initial rpm is just under 1500 on a overnight cold motor.

2. The shift happens quickly. There is no delay.

3. The engine does not appear to lifting from the rear mounts. There seems to be a normal amount of front to back engine rocking under torque load.

4. The tranny seems to hit hard in drive, as well.

Also, disreagard my question about the noisy fuel pump. This turned out to be the auto level control pump cycling. I didn't know I had this feature, but the build sheet has the G67 code. Seems like the ALC system has a leak, or is it normal for it to cycle regularly at a stop?

Thanks again!

1. Initial rpm is just under 1500 on a overnight cold motor.

2. The shift happens quickly. There is no delay.

3. The engine does not appear to lifting from the rear mounts. There seems to be a normal amount of front to back engine rocking under torque load.

4. The tranny seems to hit hard in drive, as well. Thanks again!
It appears everything is normal except your cold start idle speed! 1500 rpm, is an extremely high engine speed @ cold start. Normally, cold start idle should be around 900 to 1100 rpm! Look for vacuum leaks, or have the engine scanned to record DTC's, or watch for abnormal sensor parameters.