1998 Grand Prix GTP won't shift!

It all started about last week, when I began losing power accelerating on grades. It felt really jumpy, like it was missing, or like it would lose power and then jump forward I guess. Well, this morning I pulled out my driveway and went to pull onto the highway and the engine revved like it was in neutral and didn't move. I tried putting it in reverse and got nothing, then I tried the 1,2 and 3 gears too, but got nothing. I've heard similiar problems where the answer is replacing the Cat converter, but this seems more like a transmission problem?
My transmission oil is at the right level, but maybe just a little brown... shouldn't make a huuuge difference though, right?

thanks for any help!

Welcome to AF!!

Unfortunately the transmission is gone and will need to be rebuilt or replaced. The fact that none of the gears works is usually a good indicator especially given the signs you said it displayed earlier. If you want a used transmission vs a rebuild try Ed Morad at moradautoparts.com. He specializes in GM W body cars and has good prices. Of course you will have to get someone to replace it for you.

Unfortunately the transmission is gone and will need to be rebuilt or replaced. The fact that none of the gears works is usually a good indicator especially given the signs you said it displayed earlier. If you want a used transmission vs a rebuild try Ed Morad at moradautoparts.com. He specializes in GM W body cars and has good prices. Of course you will have to get someone to replace it for you.
Hello GTP Dad,

With a used transmission, isn't there a concern that you can end up with high mileage and/or the same problems waiting to happen on it? The catastrophic transmission failure on these 4T65e tranny's seems to be a common theme among GTP owners. The particular car in the post above did throw a P0742 code, but it certainly seems to big a bigger problem than a TCC solenoid.

A local tranny shop was going to charge about $1400 for a rebuild until he saw that it was supercharged, then the price went up to $2100+. Is he in the ball park there? I have seen rebuilt 4T65E's on the web for anywhere from $650 to $2200 plus shipping/core but they don't reference "supercharged".

Any insight would be appreciated. I'm in Alaska so shipping tends to get a little high.

Troy

A local tranny shop was going to charge about $1400 for a rebuild until he saw that it was supercharged, then the price went up to $2100+. Is he in the ball park there? I have seen rebuilt 4T65E's on the web for anywhere from $650 to $2200 plus shipping/core but they don't reference "supercharged".

Any insight would be appreciated. I'm in Alaska so shipping tends to get a little high.

Troy

To start find another reputable transmission shop. Way out in left field. :shakehead The price jump is unfounded just because you have the supercharged engine and the 4T65E-HD autotransaxle. Both the 4T65E and 4T65E-HD transaxles are the same less the beefier differential and final drive gearing which is 2.93:1. Also, the passenger side axle half shaft is heavy duty but that should have no bearing on the price since it is technically external to the transaxle.

You can get a totally rebuilt high performance HD transaxle from ZZP for $1599.99 plus core charge which is reasonable. See link below.

Click here (http://www.zzperformance.com/grand_prix/products1.php?id=150&catid=105)

Okay, that's really good to know.

I checked out ZZP and it looks like the warranty is void unless they do the install, which is not going to happen for the obvious logistical reasons. I notice the tranny comes stock with dual chain 2.92:1 gears and a host of options, which I don't fully understand the benefit of. I don't think I would need all the extra beef since it wouldn't be raced. I'll have to call ZZP and get more info. The tranny sounds tough, which would be nice not worrying about it.

Could you refer me to some documentation for pulling the transaxle?

Thanks for your help,

This how the warranty is covered. You can do the install and it does not void the basic warranty. The biggest issue is see if they ship to Alaska and what the freight charges are.

"Warranty is 90 days on shipped transmissions and 180 days on transmissions installed by Certified Transmissions."

The best documentation to use to replace the transaxle DIY is the GM FSM. Not exactly a fun job but can be done.

I have to agree with BNaylor on this. The ZZP transmission is the way to go especially if you plan on doing some hot rodding with your car. It has much heavier components and will withstand the riggers of full throttle blasts and costs less than a rebuilt one from the tranny shop. I would also find another shop and see what kind of price you can get from them. Also try to find a garage to do the install as you may be able to find someone to do the job for a couple hundred bucks. It is worth the cost especially if you don't have a good place to work.

Thought I read somewhere on ZZP that if you can get your car to Michigan, not sure where the OP lives, that ZZP will install for free. Is this true?

Thought I read somewhere on ZZP that if you can get your car to Michigan, not sure where the OP lives, that ZZP will install for free. Is this true?

I recall they charge at least $400 if you bring it to them so it is not really free. The OP and the second person addressing the issue both live in Alaska from what I can see. It looks possibly like they are related...father and son or it is just a strange coincidence?