Trans failure question...

Greg Reimer 7376 · 06-08-2023, 11:54 AM

Good points, all of you. I'll snag the trans out, drain it and drop the pan, then see what broke. I need to check the engine as well. It got rather high for an instant when it failed, I don't think there are any bent valves, but a compression test and a leak down test wouldn't be a bad thing to do anyway. It has a pretty good engine in it and I want to be careful of that. It was kind of noisy when I was being towed back to my pit space, although it was quieter by the time we got there. I originally thought it might have been a rear end failure, but that wasn't the case. Ring and pinion looked very good, it rotated ok, so the cover went back on and new lube went in. Oil looked great also. I suspect planetaries also.

Greg Reimer 7376 · 06-08-2023, 07:01 PM

Well, opened the hood to check some things.First easy to fix thing was the fact that the alternator belt was missing. Must have happened off the line when the trans let go. That's fixed, so l lit it off and tested it going through the gears. No Low, no High, no reverse. So, it would seem that the input shaft or the clutch drum is probably out. Fluid looked good on the stick, I need to drain it and drop the pan for a better look. If the converter failed, it would still have a sensation in gear, even though it might be very sluggish. I'll slip the trans out and check a few obvious things like that. It's a Powerglide. How hard can that be to fix? I didn't notice any bad noises when steering the car back to my pit space from the starting line,You don't really get any feeling of anything trying to engage as you shift from Lo,Drive, or reverse. Even a broken converter will transmit some sensation of gears engaging. I'll get to the bottom of it yet. Watch me!

David Lee · 06-08-2023, 08:49 PM

did you break at irwindale?

Greg Reimer 7376 · 06-08-2023, 08:56 PM

Yes. Second time only, left lane. Ended my day nice and early. Were you there?

David Lee · 06-08-2023, 09:17 PM

Quote:

Originally Posted by Greg Reimer 7376

Yes. Second time only, left lane. Ended my day nice and early. Were you there?

no, but seeing where you live, it was an easy jump.

i am thinking of buying a 2000 era camaro or mustang to have fun there

ss3011 · 06-08-2023, 09:24 PM

One easy test is with a Line Pressure gauge, Check the pressure in each gear range.

Steve Stasko · 06-09-2023, 08:25 AM

You're correct in your assumption about the Powerglide being easy. I've done 727's, and the Glide takes about half the time.

I broke a 1.76 planetary and it did still lurch when you put it in gear, so a good chance you broke the input. Are you using a stock input shaft? I would upgrade to at least a 300M if so, though a Vasco is best.

If the planetary is good, make sure you check the end play on the gears in it while you're there. I seem to recall there should be .02-.03" between the gear and the planetary housing.

Eman · 06-09-2023, 11:02 AM

Don't know if you're into the diagnosing before pulling. A third option behind input shaft and planetary breaking is pump gear breaking. Just had a friend's car do this. Pressure test would confirm pump operation if you wanted to know before pulling. Not really needed to diagnose as whatever is broken will be apparent when pulled. Shaft can break and leave a piece in the converter.

Greg Reimer 7376 · 06-09-2023, 05:15 PM

Several years ago, i had the drive lugs break off the inside of the inner front pump gear.It resulted in a zero oil pressure situation real fast out of the blue. It was in my Chevelle wagon, same engine/trans combo. When i pull the trans and inspect it,I'll know more.

06-08-2023, 11:54 AM	#1
Greg Reimer 7376 VIP Member Join Date: Nov 2008 Location: Glendora,Calif. Posts: 1,135 Likes: 172 Liked 704 Times in 218 Posts	Re: Trans failure question... Good points, all of you. I'll snag the trans out, drain it and drop the pan, then see what broke. I need to check the engine as well. It got rather high for an instant when it failed, I don't think there are any bent valves, but a compression test and a leak down test wouldn't be a bad thing to do anyway. It has a pretty good engine in it and I want to be careful of that. It was kind of noisy when I was being towed back to my pit space, although it was quieter by the time we got there. I originally thought it might have been a rear end failure, but that wasn't the case. Ring and pinion looked very good, it rotated ok, so the cover went back on and new lube went in. Oil looked great also. I suspect planetaries also.

06-08-2023, 07:01 PM	#2
Greg Reimer 7376 VIP Member Join Date: Nov 2008 Location: Glendora,Calif. Posts: 1,135 Likes: 172 Liked 704 Times in 218 Posts	Re: Trans failure question... Well, opened the hood to check some things.First easy to fix thing was the fact that the alternator belt was missing. Must have happened off the line when the trans let go. That's fixed, so l lit it off and tested it going through the gears. No Low, no High, no reverse. So, it would seem that the input shaft or the clutch drum is probably out. Fluid looked good on the stick, I need to drain it and drop the pan for a better look. If the converter failed, it would still have a sensation in gear, even though it might be very sluggish. I'll slip the trans out and check a few obvious things like that. It's a Powerglide. How hard can that be to fix? I didn't notice any bad noises when steering the car back to my pit space from the starting line,You don't really get any feeling of anything trying to engage as you shift from Lo,Drive, or reverse. Even a broken converter will transmit some sensation of gears engaging. I'll get to the bottom of it yet. Watch me!

06-08-2023, 08:49 PM	#3
David Lee VIP Member Join Date: Oct 2007 Posts: 1,168 Likes: 487 Liked 346 Times in 126 Posts	Re: Trans failure question... did you break at irwindale?

06-08-2023, 08:56 PM	#4
Greg Reimer 7376 VIP Member Join Date: Nov 2008 Location: Glendora,Calif. Posts: 1,135 Likes: 172 Liked 704 Times in 218 Posts	Re: Trans failure question... Yes. Second time only, left lane. Ended my day nice and early. Were you there?

06-08-2023, 09:24 PM	#6
ss3011 Senior Member Join Date: Feb 2002 Location: Southeast Michigan Posts: 909 Likes: 70 Liked 239 Times in 114 Posts	Re: Trans failure question... One easy test is with a Line Pressure gauge, Check the pressure in each gear range.

06-09-2023, 08:25 AM	#7
Steve Stasko Member Join Date: Jul 2011 Location: Western PA Posts: 455 Likes: 13 Liked 274 Times in 143 Posts	Re: Trans failure question... You're correct in your assumption about the Powerglide being easy. I've done 727's, and the Glide takes about half the time. I broke a 1.76 planetary and it did still lurch when you put it in gear, so a good chance you broke the input. Are you using a stock input shaft? I would upgrade to at least a 300M if so, though a Vasco is best. If the planetary is good, make sure you check the end play on the gears in it while you're there. I seem to recall there should be .02-.03" between the gear and the planetary housing.

06-09-2023, 11:02 AM	#8
Eman Member Join Date: May 2014 Location: E TN Posts: 473 Likes: 16 Liked 133 Times in 76 Posts	Re: Trans failure question... Don't know if you're into the diagnosing before pulling. A third option behind input shaft and planetary breaking is pump gear breaking. Just had a friend's car do this. Pressure test would confirm pump operation if you wanted to know before pulling. Not really needed to diagnose as whatever is broken will be apparent when pulled. Shaft can break and leave a piece in the converter.

06-09-2023, 05:15 PM	#9
Greg Reimer 7376 VIP Member Join Date: Nov 2008 Location: Glendora,Calif. Posts: 1,135 Likes: 172 Liked 704 Times in 218 Posts	Re: Trans failure question... Several years ago, i had the drive lugs break off the inside of the inner front pump gear.It resulted in a zero oil pressure situation real fast out of the blue. It was in my Chevelle wagon, same engine/trans combo. When i pull the trans and inspect it,I'll know more.