Car is Stopping Dead.. Locking Up...Help

J

jg61hawk

Senior Member
I have a 1929 Roadster. I was going forward and all of sudden it locked up at about 5 MPH and made some bad sounds. It will go backwards fine. I put it in neutral and pushed it forward and the right side rear wheel locked up after a few feet. If I go backwards it seems to "reset" and I can go forward a few more feet but it locks up again.

I watched the engine fan while pushing forward and when it locks up the fan does not move, indicating it's not slipping into gear. It also locks up with the clutch engaged or not engaged.

I thought maybe the emergency brake is somehow activating but it rolls backwards fine but not forward. I backed home about a block.

When it is locked up I can put it in first, second or third and the transmission seems like it is working perfectly, trying to pull against the reason the car is locked. Help is appreciated.

I'm thinking either right rear emergency brake or something in the rear end is binding up. Is the right rear the drive wheel?
 
Check the easy stuff first. Put the rear end on jack stands and see if the wheels engage in all gears, engine running.
 
Sounds like rear diff... Drain the fluid see what comes out metallic etc.... Remove the fill plug and look at the ring gear teeth with a light...
 
Broken teeth ring gear. Drain rear end or take a small magnet and lower in drain plug see if teeth pieces attach, I know went thru same problem a few years back. good Luck.
 
My 29 Tudor did the same thing when I first bought it. Turned out to be the parking brake linings were all messed up. In fact my right rear lining was held in place by only one rivet.

Hopefully it won't be bad gears in the rear end, but if it is, then now is a good time for the 3.27 ring and pinion.
 
Thanks for the replies. My thoughts are to definitely start at the right rear as that locks up when pushing it forward. If the brakes look good I'll remove the brakes and leave the key in the axle to the drum. If it still locks up can I remove the drive shaft on an A? In other words I will want to segregate the rear differential from the transmission to see where the lock up is occurring?

So I need answers to the following: Do both wheels engage from the differential (I think they do from reading some books). Can I pull the drive shaft without removing the entire rear end? Is there a way to segregate the rear from the transmission? I'm thinking if it is not the brakes and I can segregate the trans and rear I can spin the wheels and see if the rear locks removed from the trans...if it does the rear is bad if it does not the trans has a problem. Am I thinking correctly? Ideas?
 
If the trouble is in the gears, then I'd pull the complete rear end, but you can remove the spring shackles, right brake hub/drum, and the connecting parts on the left backing plate, then pull the axle/differential assembly out the left side.

Do you have some Model A books?
 
Santa is checking his Naughty and Nice Book. If you have been Naughty it will be your Diff. If you have been Nice it will be your brakes and an easy fix. My guess is it will be your brakes. Have a nice Christmas from the land Down Under. No snow here, Temp is 86 degrees at 8.45 am in the Tropical North.
 
As noted it could be a number of things.
My suggestion would be in the following order.

1. Pull drums and make sure brakes are ok and that e-brake arms, springs , toggle links etc are retracted and against spring tension
At th same time you can ensure your axle ends and keys are ok
If you broke an axle key or axle you actually wouldn't go anywhere and the trans and rear axle would rotate but no forward motion

2. As Mitch noted pull the drain plug on rear axle and trans and look for any broken teeth. It is very unlikely even if you had a broken tooth on the rear axle gears that it would come out in the drain

3 if you haven't found any tell tale signs yet remove the transmission top and inspect the gears . If the gears are ok I the trans and brakes and all looked good it is probably rear axle related . Broken ring gear, bearings on driveshaft, etc

Be methodical in your approach to narrow it down
I love these kind of troubleshoots .

Best of luck and keep us posted
Larry Shepard
 
Last edited:
jg61hawk said:
Thanks for the replies. My thoughts are to definitely start at the right rear as that locks up when pushing it forward. If the brakes look good I'll remove the brakes and leave the key in the axle to the drum. If it still locks up can I remove the drive shaft on an A? In other words I will want to segregate the rear differential from the transmission to see where the lock up is occurring?

So I need answers to the following: Do both wheels engage from the differential (I think they do from reading some books). Can I pull the drive shaft without removing the entire rear end? Is there a way to segregate the rear from the transmission? I'm thinking if it is not the brakes and I can segregate the trans and rear I can spin the wheels and see if the rear locks removed from the trans...if it does the rear is bad if it does not the trans has a problem. Am I thinking correctly? Ideas?
Click to expand...

Your problem only occurs when under load, so pulling the Drive Shaft won't tell you anything other than that the engine runs when not under a load, which (if I read your earlier post correctly) is already a known fact.

The Brake is most likely the point of failure, so stop thinking and check that first. We can get into differential diagnosis later, if necessary.

Here's a tutorial (apologies for the source!)
https://www.youtube.com/watch?v=K4JhruinbWc
 
Repeat: unscrew the fill plug and look at the ring gear teeth... That's the easiest thing to do
 
Last edited:
My coupe did the same thing only both rear wheels locked up. Had 2 teeth of the pinion and 3 off the ring gear.
 
Mitch//pa said:
Repeat: unscrew the fill plug and look at the ring gear teeth... That's the easiest thing to do
Click to expand...


Mitch, sorry I missed that point and I agree with you .
A small light will aid him in checking the ring gear. It is possible a pinion tooth could be broken as well as I have seen that. Even pinion bearings coming apart. This one isn't too hard to pinpoint in my opinion
Larry
 
My 29 coupe was trying to lock when coasting, it would pull with no problem. When I disassembled rear end I found both pinion retaining nuts and lock loose on drive shaft. It had a 4-11 gear set in it. When I put it together I went with a 3-54 gear set and new bearings and u joint. Dwayne
 
You must log in or register to reply here.
Back
Top