Transmission Mount Issues?

[Rodster]

Hi everyone, I scored a 2006 Lucerne at a local GM Dealer in Sarasota, Florida. Awesome car, very stylish, with ultra low miles (72K) and the paint looks great. I'm the 4th owner and the car doesn't have a single door ding, unbelievable for a car with four owners.

I used my friends garage lift and replaced the transmission fluid and filter. I have at least two mounts that are broken, the front mount and the torque strut mount. I ordered from RockAuto the OEM front and rear engine mounts and the torque stut mount. Whether the rear engine mount is still intact, I plan on replacing it anyway.

My question is, the transmission mount has been discontinued by GM. I placed a special order with SummitRacing.com for the OEM transmission mount. My question is, do the transmission mounts hold up or do they fail regularly like the engine mounts? So my plan is, if I can get the GM transmission mount from SummitRacing, I plan on replacing all 4 mounts.

 

[2007LucerneCXL]

Transmission mounts usually out last the motor mounts, but if the other mounts are gone it's possible the transmission mount had additional stress.

Be mindful that some owners use the cheapest ebay or foreign country mounts that have a short life expectancy. The post that have multiple replacement never mentioned the manufacturer or where they were purchased and it's always the vehicles fault for cheap buying decisions.

 

[Rodster]

Transmission mounts usually out last the motor mounts, but if the other mounts are gone it's possible the transmission mount had additional stress.

Be mindful that some owners use the cheapest ebay or foreign country mounts that have a short life expectancy. The post that have multiple replacement never mentioned the manufacturer or where they were purchased and it's always the vehicles fault for cheap buying decisions.

I totally agree which is why I always buy and suggest OEM parts. The three engine mounts I purchased and received from RockAuto were AC-Delco parts. Unfortunately they don't carry the OEM transmission mount, only aftermarket. I placed a special order with SummitRacing.com and they say the part should arrive the beginning of June. If they do get it, that's when I'll replace all four mounts.

Btw, what are the signs and symptoms of a bad transmission mount?

 

[2007LucerneCXL]

Engine/transmission lift, thumping on hard acceleration, thumping on turning, possible vibration at speed. Depending on how bad the other mounts are the transmission mount may be something that can be bad to severe on how it's performing and what movement the vehicle is driven highway vs stoplight etc.

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[Rodster]

Engine/transmission lift, thumping on hard acceleration, thumping on turning, possible vibration at speed. Depending on how bad the other mounts are the transmission mount may be something that can be bad to severe on how it's performing and what movement the vehicle is driven highway vs stoplight etc.

A few of days after I bought the car I noticed a thump when accelerating from a stop. It felt like I got hit from behind which led me to check the engine mounts. The worst mount that's severely cracked is the torque-strut mount.

I also had an intermittent slippage of the transmission. It was a very short slippage and I plan on scanning for a solenoid issue. What's weird is that after I verified that the front engine mount had failed, all the problems went away. The thumping and slippage have not reappeared for over a month. I even did a hard acceleration from a dead stop and NO thumping or slippage, weird!

 

[2007LucerneCXL]

I listed the general felt problems but each vehicle may or may not have them depending on the conditions of the car. The GM 4T65E has it's own list of problems with lack of owners maintenance probably the #1 lol, but there is TSB on the magnets upgrade, TransGo kit and line clamp that can help in keeping it going along with the fluid and filter changes.

I've had some "one time only" issues no codes on any component or stored that never repeated in 5 years. Again this is my vehicle so can't say it applies to all, but I have the magnets and do regular trans fluid/filter changes. I assumed that the Lucerne was just having a senior moment lol.

https://m.facebook.com/story.php/?story_fbid=648224082314455&id=225702411233293

 

[Rodster]

I listed the general felt problems but each vehicle may or may not have them depending on the conditions of the car. The GM 4T65E has it's own list of problems with lack of owners maintenance probably the #1 lol, but there is TSB on the magnets upgrade, TransGo kit and line clamp that can help in keeping it going along with the fluid and filter changes.

I've had some "one time only" issues no codes on any component or stored that never repeated in 5 years. Again this is my vehicle so can't say it applies to all, but I have the magnets and do regular trans fluid/filter changes. I assumed that the Lucerne was just having a senior moment lol.

https://m.facebook.com/story.php/?story_fbid=648224082314455&id=225702411233293

Thanks for the info. It's a shame that the first thing I did regarding the intermittent/quick slippage was to replace the ATF and a new filter. I used Valvoline Dexron VI ATF. After I replaced the ATF/Filter, the intermittent slippage was still present. I checked the fluid level at that time and it was slightly less than a half qt low even after running the transmission thru the gears and rechecking the fluid level at the time of service. Since I have topped off the ATF, no slippage. So maybe it had something to do with a little less than a half a qt low, or as you say, it had a senior moment.

I will try and order the magnet you suggested. If the problem reappears and it's a solenoid I may consider dropping the pan and replacing the magnet.

Edit: How many magnet(s) are required?

 

[2007LucerneCXL]

2, see the link

https://m.facebook.com/story.php/?story_fbid=648224082314455&id=225702411233293

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