The Stovebolt Site Forums The Shop Area Engine Shop Help! My overdrive went belly up

I have (at least I think) a 1958 Borg Warner 3speed/Overdrive in the 41 Chevy.

Last week I was driving home on the Autobahn and everything was fine, till I heard a sharp "chlunk!" and suddenly the overdrive wasn't in overdrive anymore.

It´s nothing electrical - thou the lever (and the handle on the dashboard) is in overdrive position, there is no freewheeling anymore.

Still drives, but it´s like with the normal tranny.

It took plenty of 3 letter words to massage the whole thing in the car and I hoped that I never ever have to pull it out again.

Any ideas?

Thanks, Frank

Frank, I have about 42K on a '62 3sp+od so I will be eagerly awaiting the responses on this one. Unfortunately I think you're going to have to pull it and go through the overdrive.

This site may be helpful. Although a Plymouth, the overdrive units are the same as ours.

Several links could be of help here.

I have a '69 all-synchro overdrive transmission that I've been threatening to rebuild for 4 years so your challenge may just kick me into gear to finally rebuild the unit. I'm a daily driver year round only vehicle so it would be good 'head insurance' to have the back-up ready to install in the event of a catastrophic failure.

Keep us posted,
Cosmo

Quick, on topic question. With the borg warner you guys are running, do you cars, or trucks have open drivelines? -no torque tube?

Yeah, converted to a open driveline and a 58 Truck rear end.

Frank

Whenever you get noises like you describe and the OD stops working it can't do it any good by continuing to drive it. Parts wear out and stuff breaks, it's a normal process. A tear down will be in order. Let us know what you find. There are several of us on this site that have experience rebuilding these units and can help.
Fred

With electrical working & lever locked in odrive & no odrive or free wheeling, sounds like mechanical problem in odrive unit. The 1955 Chevy Truck Shop Manual, reprints sold by many aftermarket suppliers, has a whole section on the odrive trans including rebuilding and trouble shooting. I highly recommend getting a manual.

I made my floor jack serve as a trans jack by welding a "basket" using 1/4" square steel rod & 1/4" steel plate to hold the trans with a 1 1/2" diameter short round steel rod on the bottom of the basket that fits into the hole on my 2 ton floor jack. It makes it easy to lift the trans & easy to roll the trans in/out during R&R. I drilled a hole in the plate steel for the trans drain plug to fit into so the trans fits securely in the basket. Buy a trans spline plastic replica alignment tool (when you buy the manual)to align the gear in the center of the clutch plate (if you moved the clutch pedal)for getting trans spline to easily slide in when intalling trans. No more need for 3 letter words.

When filling the trans with fluid, always pull the side plug on the overdrive section and fill it first, before filling the trans gear section. Filling the trans gear section with fluid without filling the odrive section first can ruin the odrive parts before the fluid works it way into the odrive section when driving. So says my trans rebuilder who has been rebuilding them for over 50 years. I have had the 3 speed odrive in my daily driver 54 1/2 ton for over 30 years and love it - 70 mph & under 2k rpms with the original 235. Good luck.

I have been running overdrives in y-blocks for over 45 years. The backside almost bullet proof. But it is machinery and machines break. I would suspect that the back section may have run dry. Fords used a BW front section while Chev used their own front except for the rare heavy duty option. The back section is the same except for the main shaft having different splines. Overdrive repair manuals are on eBay all the time. Buy a repair manual and study it. The planetary gears are on eBay occasionally, but used gears out of a Ford will work. And they are very available... I just noticed you are down near München. Maybe parts are not so available there. Buy a book and tear it down and figure out what you need. It would be cheaper to buy just the parts you need.

I already have all the manuals and understand most of it.
I found out, that the oil on the rear (overdrive) section was pretty low. Duh!
Hope it did not too much damage.

Regarding the oil. My manual says "use straight sae20 engine oil - never use hypoid.

WTF? SAE20 in a tranny? Do they mean for the front and back section? As far as I know they are connected so the oil can go back and forth. Can someone please shine in and explain that to me?

Thanks, Frank

Could be the blocker ring. Had one go in mine. It spun in the housing, taking a chunk out of it in the process. Did just as you describe. The only way to know for sure is to tear it down. Not really a hard trans to work on, though. You may want to see about getting a parts transmission, perhaps from e-bay. doesn't need to have a good main trans, as long as the overdrive is good. I see them for around $100-$150.
The manuals I have (Factory manuals, '55-'59) all say 90 wt, regardless of transmission.

I copied a link from a Studebaker club that was published by BW before GM started using over drives. http://www.studebakerclubs.com/NorthGeorgia/Overdrive.pdf Page 19 addresses lubricant. It calls for 40w or 50W motor oil or straight mineral oil. I have run over the road trucks for over 45 years and the past 20 years I have used 50 W synthetic. This is what Fuller and Meritor requires to preserve the warranty. Before then I used 90 W mineral oil in transmissions. I use the 50 W synthetic in my Ford overdrives. When 90 W mineral gets hot, it is about the same viscosity as 50 W. Synthetic. I haven't seen 90 straight mineral around in quite a while.

If it's like my father inlaws 55 Ford, all you'll need is the solenoid that shifts it into overdrive,
Scott

The fact that he heard a clunk troubles me. It would be nice if just a solenoid would fix it because the whole transmission is a lot of trouble to remove and reinstall. I even have Hurst shifters on mine which makes it even more complicated.

As above Frank stated that the problem was not electrical.

I've used 80-90 wt. synthetic for 10 years now, careful to fill both sides, transmission and overdrive.

Here are most of the manuals online for free:

http://speedprint.com/deves50/overdriveindex.php

regards,
Steve
New Orleans

But he doesn't state how he proved it's not electrical. Sounds like the solenoid to me,
Scott

When I heard that "chlunk!" it suddenly also went out of freewheeling thou the lever is still in overdrive position.

The solenoid is fine.

Maybe the spring of the collar broke or something like that.
I guess i have to hulk it out and take it apart.

So it´s motor oil in the tranny huh?
Does anyone know why the manual says UNDER NO CIRCUMSTANCES Hypoid type oil?

Frank

The transmissions in our over the road trucks were very difficult when someone mistakenly put hypoid in them instead of straight mineral oil. Now we use 50 w synthetic. Also, the the overdrive in every vehicle other than GM uses a Warner front section. Chev mated their own front box to a Warner overdrive tailshaft. The Warner boxes used brass synchros which were attacked by the hypoid gear oil. Have fun removing it. They weigh over 100 lbs.

100 lbs, no way, 70 at most.

Frank,

The rear overdrive section and the front transmission gears section are connected and use the same oil. Fill the rear overdrive section up to the fill hole, put the plug in and then immediately fill the front transmission gears section up and put the plug in and you will be assured both sections have the proper amount of oil. I have always used the 90 weight recommended in the manual and try not to go more than 15,000 miles between changes. It is pretty cheap at the auto parts store. I live in Southern California where we rarely see 32 degree weather. Experienced transmission rebuilders tell me I should use the lighter weight oils if I ever move to a cold climate, in order to avoid damaging the overdrive parts.

Update? Inquiring minds would like to know status of your transmission.