Towing C3 question

If I tow my 75 Vette on a tow dolly do I need to disconnect the driveshaft. Trans is th400. Thanks in advance.

Yes

2 minutes. Nice.
Thanks. I figured as much but wanted to be sure. More help here than the Vette forums.

How far? GM trannts are pretty tolerant of towing. If it was local I wouldn't worry about it.

About 40 minute drive, some dirt and gravel.

I would definitely disconnect.

Put the rears on the dolly? Just make sure the steering wheel locks.

rcutclif wrote: Just make sure the steering wheel locks. And the tie rod ends, ball joints, bearings, bushings, rag joint, and steering box are like new.

FTFY. I nearly lost a car that way. It darted back and forth a bit, (loose steering box I later discovered) but I thought I could control it. While very mildly attempting to avoid a retread in the road, the car I was towing tried to overtake me. It went more than 90 degrees because the tongue of the dolly smashed my tailpipe. Others do it with success, but I don't anymore.

Another thing that might be an issue with a C3 on a dolly backwards is the nose dragging. On a dirt road I might be afraid I'd get home and the nose would be missing

In reply to curtis73:

Yikes.

Yes, I'm not sure if feel confident with that setup going on the highway. Scraping the nose would be a concern as well.

Oddly enough GM says it is perfectly fine to flat tow a front drive automatic if you start it every few hours to resettle the trans fluid.

I don't see what fundamental difference there is between a GM transverse automatic (which uses planetaries as a final drive, there is no ring and pinion) and a longitudinal auto. Heck the transverse automatics are really just a RWD automatic set next to the engine via chain drive instead of behind it, with a differential stuck on the end and the left axle running through a throughshaft.

Mainly, pulling the driveshaft on a C3 sucks massively. I speak from very recent and painful experience. Diagnosing a driveline shudder on a T56-converted C3 as we speak. Err, as I type. Well not literally now, more like the thing is hanging on a lift at work, but you get the idea.

PS - T56s do not fit in C3s without either massive floor hacking or ugly driveline angles. Not insurmountable, rewards are worth it.

Trans in neutral, should be no prob.

BTW, no interstate driving. Just Vermnot back roads. Bringing to a friend's garage to pull the L48/th400 for rebuilt LT1/4l60e.

It should be fine. I agree about it being a pain to pull on the ground trying to get around the rear crossmember is tight. I would also never trust a steering column lock to tow something backwards, at the very least secure the steering wheel with the seatbelt. Column locks have a nasty tendency to pop loose at a bad time.

Can you let it idle in neutral while you tow? The problem is one of lubrication, or lack thereof while the pump is not running.

Put in drive with it running?

(Now im actually curious what that would do)

Streetwiseguy wrote: Can you let it idle in neutral while you tow? The problem is one of lubrication, or lack thereof while the pump is not running.

This has been done many times in RV circles with questionable results. Airflow can be seriously compromised directly behind a tow vehicle. Some folks hitched up their brand new toads and found that the engine overheated severely and it was (of course) not covered under warranty.

In reply to curtis73:

Years ago, a dude showed up in Saskatoon with a Corolla on the drawbar. He'd accidentally left Ontario with the gearshift in second gear.

Didn't have a great deal of compression left when it got here...

MrJoshua wrote: Put in drive with it running? (Now im actually curious what that would do)

It will destroy clutches very quickly. 1) Idle fluid pressure is very low and not enough to hold the clutches firmly together. 2) It will be constantly under engine braking and there will be a great deal of torque on the clutches. Best bet is to not have the clutches engaged at all. Not to mention, all that braking torque from the towed vehicle would tax the tow rig. Not a huge deal, but something to consider.

If it were mine, I would disconnect the driveshaft at the pinion and tie the shaft out of the way. If you were to risk it still connected, I would just take the risk without it running or in Drive. Just put it in neutral and take your chances.

The problem is, without the pump running, there is no lubrication getting to key hard parts. It isn't like a manual where the lower part of the gears are immersed in lube and carry it around. Without the pump pumping, there is little or no lube getting to moving parts.

Streetwiseguy wrote: In reply to curtis73: Years ago, a dude showed up in Saskatoon with a Corolla on the drawbar. He'd accidentally left Ontario with the gearshift in second gear. Didn't have a great deal of compression left when it got here...

I'll bet he won't do that again