Had the transmission in my A4 rebuilt back in July due to no 3-4 shift. This is the secomd rebuild in about 5 years. This time I did all Sonnax stage 2 parts with a TransGo shift kit and added a trans cooler. Came with a one year warranty.

A couple months after I got it back reverse gear started to slip. I finally got it back to the trans shop and they opened it up today and called me and said that the internal lugs are broken and I need a.new case.

The way he explained it to me is that inside the case you have your piston, then your clutch packs, then the snap ring, and the lugs that hold the snap ring are broken.

I asked how that could happen and he said hes only seen it happen when its shifted into reverse while going forward. I know this didnt happen and I baby the car.

My queston is does anyone have any idea what would cause this? Could it be an install or rebuild error that caused it? Anyone ever heard of this? Should it be covered under their one year warranty?

Also, does anyone have a lead on a Corvette A4 transmission case?

Really need help understanding what's going on here from an expert.

 

After further research, the only thing I can find that would cause the internal lugs to break is the snap ring that holds the reverse piston in place being installed wrong. If it is not indexed properly or installed upside down, the anti clunk spring can pop it out of place allowing the piston to slam against the lugs.

Went to the trans shop this morning and spoke with the guy. He was able to find a new case ($400) but doesn't want to cover it under warranty. I asked him what else could cause the broken lugs and he couldn't explain it. I explained that the only reason for the broken lugs I could see would be the snap ring being improperly installed. He couldnt give me any other explanation except he said one guy put it in reverse while going down the highway and had his break like that. BS explanation imo. He was only adamant it wasn't their fault.

I think this should be covered under their 1 year warranty as the only explanation it could be is improper installation. I have less than 5k miles on the rebuild. Gonna have a fight in my hands when I go to pick it up I'm sure.

 

Sorry, and find a new transmission shop.

 

Moved to C5 Tech for continued discussion.

 

No doubt. It makes me sick that there's no accountability from anyone today. It's NEVER their fault. It's like when I was raising my kids. When something went wrong, or was broken, nobody did it!! This trans guy should be exposed, so we ALL know who we won't have working on our transmissions.....

 

You HAVE to get some ***** here. You NEVER put the car in reverse with the car moving. Tell them that you intend to sue if they don't fix it. If they refuse, back that threat up with a letter from your attorney.

Yes in that case you may have to pay an attorney to write them a letter. And you may have to pay the attorney to sue if they don't fix it. They cannot prove that you put the car in reverse while moving -- pure speculation.

Cheaper than another rebuild and a favorable decision gets your attorney cost back.

Ask me how I know.

 

Do you really want someone working on your car because they were forced to?
Sue if you must but take the car elsewhere for repair.

 

Did some further research and the 4l60e has a reverse inhibitor switch. The switch will not allow the trans to shift into reverse while moving forward. Even if i managed to put the gear shift lever into reverse while moving forward, the trans wouldnt activate the reverse piston.

I already threatened to take the guy to court when I went to look at the damaged case. He said "we can go to court". Also, when he showed me the case someone had written on it with a yellow paint marker and put a date of 3/xx/24. Looked fresh. He pointed that out and said it wasn't gonna be covered. I told him I had a receipt in my pocket with a date of 7/11/24 so I dont know where he got that march date from. Shady....

Went to pick it up today and looks like he rethought things. I walked in and he just handed me the key and said I'm all set. i wasnt charged.

Driving home from the trans shop i stopped at a store and when I went to start the car it wouldnt turn over. Lights and dash all worked bit no crank and didnt even click. Thought it may be the nuetral safety switch so i tried in neutral and no luck. I put a jump box on it and tried and it cranked and died immediately. Did that three times and on the fourth try it stayed running. Never seen it crank and immediately die before. I amhoping they didn't screw something else up. Started fine again at home.

It is a shame that I had to fight with the guy and threaten to take him to court over a $3600 stage 2 rebuild that lasted less than 3300 miles. I did the oil change a day or two after i got it back last time becauae it had been sitting for a couple months. When i checked the trip odometer when I picked it up today it had less than 3300 miles. Ridiculous.

Hope it doesnt fail again before my warranty is up in July or im sure we will end up in court.

The shop is Accurate Transmissions in Conyers, GA. I don't recommend.

 

Also, gonna put it up on jack stands tomorrow and go over everything and check the fluid levels in trans and diff.

 

FYI, 4L60e transmissions don't have any electronics or solenoids for reverse. If the shift valve goes into reverse then reverse gets applied.

 

As someone who worked in transmission shops for years (not a builder) and dealt with warranties im going to lean on the fact this was an issue on there part and it absolutely should be covered under warranty. If things done line up right on install and they put it together usually it would show its issues pretty soon but in this case it didnt. Reverse gets more line pressure then any other gear so for it to slip does take quite a bit which is usually builder error. It's been over 10 years since I was in that industry and ive had a lot of marijuana since then so please forgive my grey area response, when you dont use it you loose it.

 

The info I found on it says there is a reverse inhibitor switch that is part of the valve body, not electronic.

 

There is no way for the transmission valve body to mechanically know the output shaft is rotating.

Any and all lockout must be done at the shifter.

 

Is this not the reason you must depress the shift **** button to get into reverse? I agree with you, btw.....

 

Yes, OP posted that if he managed to put the shifter into reverse that the transmission itself wouldn't engage reverse due to an internal interlock, which isn't true. The only interlocking is at the shifter.

 

I may be wrong because I have an A4 car, but IIRC, doesn't the M6/M12 have an anti-reverse solenoid? A trans shop confusing the 6 speed with an A4 is huge red flag in my 2 cents....