1992 G30 Transmission

I have a 1992 G30 12 Passenger van (former school bus) with a dead TH700R4 transmission. Maintenance records for this show that the transmission was rebuilt at 85K and now has quit at 135K. Just prior to it quitting now it had a rattling sound which I thought sounded like the baffles loose in the muffler. Apparently not.

My father stopped in at a local AAMCO shop that we have had good experience with and they could not believe that GM put that trans in a 1 ton van. They quoted about 2K to rebuild and upgrade it to heavy duty.

I've always known the 700R4 to be a light to medium duty trans. I did put a hitch on but only towed a small military trailer with 500 lbs in it so far. Is this trans going to be able to tow a 3500 lb trailer with this van occasionally or should I look into putting a heavier trans in?

I have a 1992 G30 12 Passenger van (former school bus) with a dead TH700R4 transmission. Maintenance records for this show that the transmission was rebuilt at 85K and now has quit at 135K. Just prior to it quitting now it had a rattling sound which I thought sounded like the baffles loose in the muffler. Apparently not.

My father stopped in at a local AAMCO shop that we have had good experience with and they could not believe that GM put that trans in a 1 ton van. They quoted about 2K to rebuild and upgrade it to heavy duty.

I've always known the 700R4 to be a light to medium duty trans. I did put a hitch on but only towed a small military trailer with 500 lbs in it so far. Is this trans going to be able to tow a 3500 lb trailer with this van occasionally or should I look into putting a heavier trans in?

A good rebuild with the proper upgrades and proper care and service should give many miles of good service.
How ever if towing loads be sure it has a good external oil cooler and tow loads out of over drive.
If you had a rattle and the transmission went dead in all gears.
You might want to check the flywheel for being broke.
I have had some flywheel break or rip out.
Pull inspection cover and see if engine is turning converter.

Post back how it goes.

When it was giving off the rattling sound, I did pull the inspection cover to check that the ring gear bolts were tight on the converter. All were fine.

Doubt that it is a broken ring gear because just before it failed, it began slipping a bit but still allowed me to pull over to a safe spot and shut it down. I would think that a broken ring gear would mean no movement at all. I will take another look at this and post back soon.

Thanks
Jim

When it was giving off the rattling sound, I did pull the inspection cover to check that the ring gear bolts were tight on the converter. All were fine.

Doubt that it is a broken ring gear because just before it failed, it began slipping a bit but still allowed me to pull over to a safe spot and shut it down. I would think that a broken ring gear would mean no movement at all. I will take another look at this and post back soon.

Thanks
Jim

You are right there.
Sounds like it is a dead duck.
Did you lose all or part of the gears?
Still have reverse?
Any metal in transmission oil pan.

I finally had this transmission rebuilt. The needle bearings had failed in one of the spider gears in the planetary. The loose gear had caused the rattling sound.

The ring gear was fine and I reused it. A new converter was installed and the van is back on the road.

I finally had this transmission rebuilt. The needle bearings had failed in one of the spider gears in the planetary. The loose gear had caused the rattling sound.

The ring gear was fine and I reused it. A new converter was installed and the van is back on the road.

That sounds like a winner.
Thanks for posting back how it went and fix.
Good Luck with it.