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Transmission, A little slip and grab

06-19-2006, 08:13 AM
I have a 2003 Bonneville SSEI. It has 103,000 primarily highway miles on it. When I bought it 9 months ago it had 87,000 miles on it. I had the transmission flushed and conditioned then. No problems until last week or two. It has slipped then locked up several times when just taking off from a stop. The fluid level is full and the fluid is clean. Any suggestions as what may be causing this? If it does need a rebuild (which I sure hope it doesn't) are there any rebuilt transmission companies that have better rebuilds than others and offer strong guarantees? Thanks in advance for your help! ---- Gary Hawk

06-19-2006, 11:31 AM
Welcome to AF!!

Unfortunately, you are a victim of the infamous tranny flush. On a high mileage transmission, more than 60K miles a flush will damage the clutch faces and ofter results in the transmission failing within 10 to 20K miles. You are not the first or the last one to be hit with this problem but unfortunately it will cost you around $2400 for a complete rebuild. I had two transmissions done at AAMCO but we have an excellent AAMCO shop in my area. There are others like Cottman Transmissions. Check your yellow pages and do some calling about warranty and etc. Good Luck!

06-19-2006, 12:57 PM
I agree it could be the flush and flushes are bad but it could be coincidental with a flaky pressure control solenoid (PCS) or something valve body related. Your tranny sounds ripe for it based on the mileage and especially with the rising temperatures. GM has had a TSB out on the launch shudder and PCS problem for awhile now.

The slipping and grabbing at dead stop during acceleration is called launch shudder.

You could get it scanned with a trans. capable scanner and see if DTC error code P1811 or any slippage code is stored. Some codes will not trigger the SES light but will store for retrieval. Basically, tranny line pressure is not being controlled properly.

I had a similar problem in my GTP and replacement of the PCS solenoid fixed it. The cost at a tranny shop will vary but the range is around $450 - $550 to include part and shop fees.

Also, you could do a pan drop and see if there is any damage in the form of excessive metal shavings or tranny pieces to help make an assessment.

A rebuild will be expensive.

06-19-2006, 08:03 PM
Does it only slip when the car is warmed up? I personally don't think flushes are bad as long as your not getting any contaminated fluid from someone else’s car. 103K your probably do for a PCS. when 4T65E's go down they go down hard most of the time.

06-19-2006, 08:04 PM
Thanks for responding. If a flush is not good on a tranny, then what is one to do in regards to service it for a longer lifespan? Only change the fluid from dropping the pan and replacing the filter? The service shops make a transmission flush sound like it is the best thing one could do to maintain a transmission if you are planning on keeping the car for the long term. I will print this off and take it to my local transmission shop. Thanks for your help!


06-19-2006, 08:05 PM
Service it every 30K and your good to go!

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