Thread: Possible Trans or Tune Problem?

So I just bought this car a couple days ago. So far am very happy with it. The seller told me that there was a shift kit installed on this car, And it was tuned, so I'm not sure if what I am going to explain has to do with it.

If I am going 60 mph and then let off the gas the car coasts at 1000 RPM

At that same 60 mph coasting when I press the gas nothing really happens until about 2500 RPM

If I am trying to cruise at 70 mph I'm right around 2900-3000 RPM.

These numbers seem awfully high does that sound about right to you guys?

You are missing 4th gear

Originally Posted by BigKev2403

So I just bought this car a couple days ago. So far am very happy with it. The seller told me that there was a shift kit installed on this car, And it was tuned, so I'm not sure if what I am going to explain has to do with it.

If I am going 60 mph and then let off the gas the car coasts at 1000 RPM

At that same 60 mph coasting when I press the gas nothing really happens until about 2500 RPM

If I am trying to cruise at 70 mph I'm right around 2900-3000 RPM.

These numbers seem awfully high does that sound about right to you guys?

welcome to owning a 3800, get ready to rebuild and put in a hardended 4th

You can just drive it if it doesn't bother you. It won't hurt anything except your gas mileage.

It's not that bad. You can replace the part if you'd like.

http://www.grandprixforums.net/how-t...ess-54448.html

TripleEdgePerformance sells the shafts.

i'm really sorry man. happened to me last year.

it will kill your gas mileage. expect 4 mpg loss highway and same city. if you have it in 3 driving highway speed the rpm needle will not go down as far as fast so that should help that part.

Bought my car at 168k....trans lost third at 172k then it completely won't out at 175k

no way your in overdrive and running at 3,000 rpm's doing 70 mph. its really a 3 speed trans with a over drive, why they call it 4th gear ill never know. the 4 th gear hub splines wear off and bye bye overdrive. like posted above, its fixable.

in o/d at 70 im only doing 1800 to 2,000 rpm


i lost 3 rd in my trans, so i had to nail it to 45 plus mph in second gear, then let off the gas and let o/d catch then i could drive at highway speeds like normal. sucked not having a passing gear lol

Hook the scantool back up and look at the calculated gear ratio. Third is 1:1 and that's what you will find is occuring. Yes the pcm selected and moved the soleniods for 4th to be engaged and yes the clutches are engaged. The splines on the shaft that the clutches drive are stripped. Which keeps 4th from engaging.

GM did a cool thing with the trans in that area.

4th hub shaft. the wider part is where the clutches sit on and drive this shaft.


The smaller splined end is what drives the trans for 4th. See the mark/much less material? I have seen these stripped smooth.

here's a question....is there a way to keep it from getting stripped? is it heat related or just wear and tear from normal use? if the fluid is serviced and filter changed on schedule will it help?

It's just normal wear and tear.

they make a hardened 4 th gear hub now, so it just the older cars that are affected by this, the new part will out last the rest of your tranny.

Originally Posted by scottydoggs

they make a hardened 4 th gear hub now, so it just the older cars that are affected by this, the new part will out last the rest of your tranny.

is it industry standard or are there some kits or parts manufactured factory quality?

ive never had to order one my self, but im sure its sold saying its hardened.

cant see why they would still make a part like that when it fails.

oh, but there are others.....

97-02 The part was not hardened. That's about when GM started seeing enough of them strip out to act on it. Starting some time in 03 (late 02 builds often have non hardened) GM changed this shaft to a hardened one. Once that went in, things were good.

Tripleedgeperformance and a bunch of other sell them as well.