Borg Warner T39 stuck in forward gears

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PecanMan

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Howdy all! I have a borg warner t39 in a 1967 IH 1100b pickup truck. I have no neutral, no reverse, and no park. It seems to be stuck in the forward gears. In reverse it acts like the transmission is locked up, and in neutral and park it goes forward just like it was in first gear. Any ideas on what could be causing this?
Thanks.
 
Firstly - have you visually verified that the column shift control lever is actuating the transmission control on the unit?
 
The BW has a mechanical parking pawl, so if you have Drive while Park is selected the shift mechanism must be out-of-adjustment or your parking pawl is broken.

Drive while Neutral is selected, I would also believe is your shift linkage adjustment is out-of whack.

Quite possibly the shift linkage is disconnected from the valve body, internal to the transmission. This would explain all three of your issues.

No Reverse by itself would be caused either by a bad rear clutch or bad read band or both.....or the above disconnected VB linkage. But you say "locked up" when in Reverse, as in Park, correct? This again points to shift linkage issues.

I would drop the pan and investigate AND be sure the shift linkage is not damaged, burned on the exhaust pipe, etc.
Disconnect both ends of the linkage and operate the linkage to see it it operates freely.
Then operate the trans from the outer lever without the linkage attached and see if all the positions are there or not and functioning properly.
 
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I took the linkage off and moved the lever coming out of the transmission by hand and I still had the same results. I then dropped the pan and took a look at the valve body but all the linkage was connected. When I turned the transmission by hand, the park claw would jump teeth rather easily so that was probably the reason I was still able to go forward while in park. Reverse feels more like the transmission is trying to go in reverse and first gear at the same time(the engine sounds like it's under load and won't rev up).
 
Then I'd say you have a problem with the rear band with those symptoms.

Park pawl mechanism is damaged too.

Looks like rebuild time.

EDIT: You could have a problem with the valve body, particularly the manual valve.
A rebuild & cleaning of the VB could be accomplished first. Also the rear servo.
 
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I have the tranny out and noticed that if I turn the tail shaft the input shaft turns the same direction. Should it do this or should I be able to turn one shaft and hold the other? Could this also be a result of the rear band malfunctioning?

Also, do you know where I could get any information about rebuilding this?
 
PecanMan said:
I have the tranny out and noticed that if I turn the tail shaft the input shaft turns the same direction. Should it do this or should I be able to turn one shaft and hold the other? Could this also be a result of the rear band malfunctioning?

Also, do you know where I could get any information about rebuilding this?
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With the transmission out, in unknown gear selection and no hydraulic pressure applied, it tells you nothing.

There are tests you can do with air pressure to determine if the clutch packs & bands are applying & releasing.

As for rebuild info, you can search the internet as well as I can. I think "BW-35 or BW35" and similar search terms will find lots of info. Keep in mind, this transmission was used in many cars of the day, including foreign cars.
Example: AMC, Studebaker, Jaguar, Rover, Triumph, Citroen, Volvo and others.

I do have some service manuals that I could share, all data that I found on the internet.

EDIT: PM me your email address and I can send them to you.
 
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The vacuum modulator was bent up and when I took the valve body out I noticed the rod out of the modulator was in a bind and was definitely not able to function properly. Could this possibly cause the symptoms that I was describing?

I did try an air test and according to the manual for a 35 that I found online the clutchs seemed to function properly.
 
The modulator effects the shifting, so it would be a cause of your shift problems but not the Park issue.
 
Well, without actually having the unit out on the bench to look at it personally, I would gander the front (forward) clutch is welded. That would produce the results that have been put forth.

If I had my transmission manuals handy, I could be more precise. The bane of living in an apartment, I guess.
 
Also, do you know where I could get any information about rebuilding this?
*
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The Service Manual has indepth information on the particular variation used in IH platforms. European models are not like the old iron bodied ones in Scouts and trucks.

Parts are still available. I've checked with Portland Transmission Exchange in Oregon and a repair kit, frictions and TQ, run about $160. Northwest Transmission Parts in Ohio is a favorite for the Studebaker and AMC crowd that still has the iron body versions.

The parking pawl problem might be something as simple as the pawl spring. I got a transmission that was "locked" and all it turned out to be was the spring was off the park pawl. The rest was is in mint condition; as somebody took care of it or it had low miles and light duty. I plan to use it someday.

Without looking, just because both shafts turn does not mean clutch failure. Tight clearances and cold oil can have enough "grab" that one turns the other. Hold one, and try turning the other. It will take some effort, but if one can turn with the other held, you should be okay.
 
I have the IH Service Manual for this transmission, CTS-2494-H.
For IHC Codes: 13039 (T-39), 13049 (T-49) and 13409 (T-409).
If someone needs it, they could PM me.
Include your email address.
 
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