'48 plymouth incident while towing

[Roundeye]

I just acquired my grandpas '48 plymouth biz coupe. I went to load it on a car dolly and told my dad we needed to disconnect the drive shaft. He said because it was a manual we didn't need to. Any how we were pushing it up on the tow dolly and it moved pretty easy. So I started driving and it pulled easy but the tach on the truck was a little higher than I thought it should be but then got on the highway and in no time there was smoke coming from the back of the plymouth. I pulled over and felt the rear end, it was hot and had black ooze coming out by the pumpkin. I disconnected the drive shaft and off we went. I noticed right away the tach on the truck was 1000 rpm less than it was previously. So is there a pretty good chance I messed up the trans and rear end?

[Plymouthy Adams]

if the car was out of gear and there was oil in the rear end..an item you should have checked in hindsight...you should not have had an issue towing the car on a dolly..however...by the simple fact that you state when the driveshaft was disconnected and away you went without probs..the rear gear was not the issue...was the car in gear and maybe smoking a clutch..or the e-brake left on and smoking the band?

[TodFitch]

My vote, with the limited information given in the post, is for the hand brake not being fully released.

[Don Coatney]

E-brake and or clutch slipping does not explain the black ooze coming out of the pumpkin. The fact that disconnecting the drive shaft made the problem disappear leads me to believe that the rear U-joint may have been the problem.

What did the smoke smell like?

[1941Rick]

Without or with the driveshaft the diff will still turn while being towed.

something missing here?

[Roundeye]

Didn't actually smell the smoke but it was a grayish color and I checked the e brake it wasn't on. Never really messed with a manual on the column so had no idea if it was in gear or not and didn't figure it would matter if I disconnected the driveshaft. I pulled the car with driveshaft connected for about 5 or 6 miles and didn't go over 60.

[Uncle-Pekka]

As Tim told: If the gear is on neutral, hand brake released and proper oil in the transmission case and rear end pumpkin as well, you can tow this car for thousand miles without no harm to transmission.

The manual transmission is splash lubricated any way, thus it does know which way it is being pulled.

Automatic has oil pumps, different ball game.

Must be something stuck if parts heat till smoke comes out...

Thus you had the prolem there before you started towing, it only came visible when wheel were rolling.

However, you say taking out drive shaft released the transmission?

In this car, I cannot think not many causes for such:

- hand brake is commonly stuck, but the the smoke comes first from brake lining

- If gear was on, the clutch plate should not burn, because fluid drive should take majority of the friction heat...

- would it been universal joint you would burn your hand while disconnecting

- If it really was rear axle housing which was hot, my best guess is your rear axel inner bearing has seized & burn. Why it stopped when you realeased drive shaft? - Well, what if all the oil was burn by that?

I hope for the best for your car. I also will stay tuned and anxious to learn what really went down . Please up-date when you will take her in work shop and check parts.