Got a BW11 question..

rangerslim

rangerslim

New member
Got a couple questions with the bw11..mine is behind a 232 six and I bought this trans. From behind a v8. I replaced front and back seal and pulled the pan to take a look and it looks perfect, no metal or anything. But when I drive it, it does not go into second unless I manually shift it or tach it real high...will not shift into drive until I run it a couple miles, then it will shift fine from second to drive....just will not go from first to second....I noticed the modulator on this one looks nothing like the one that was on my original trans. That I pulled out.thanks

oh, it's a 71' 800B. And when I've driven it a couple miles it will shift out of first but it seems like it's missing second all together and trying to go into drive. This transmission doesn't slip whatsoever. And I haven't attached the wire on the side of it for the kickdown either, thanks.
 
Did you by anychance pull the governor from the transmisson when you installed the seal? In looking through an old intertational fleet service news letter dated 03/24/1969.
Governor installation on the t-26,27,28,t-39,t-49 and t-409 is of the utmost importance. Due to the fact the governor can be installed incorrectly on the transmisson.
The governor cover must face toward the front of the transmisson on models t-26, t-27 and t-28, while the governor cover must face toward the rear of the transmisson on models t-39, t-49 and t-409.
If the governor is not properly installed, the hole in the governor counterweight will not index with the hole in the output shaft, thus resulting in erratic shifting of the transmisson.
You probably have the t-39 in your unit and from the photo it looks like the bolt on boss on the governor has a plate on it that should face to the rear of the transmisson.
 
No, I have not pulled the governor. The seal was an in/out deal at the back...the modulator on the back is different from my orginal one and I pulled the rod out of both and the rod out of my orginal trans. Is almost 1/2" shorter. I got this trans. From behind a 304 v8. I'm leaning more towards this being the problem, I think...
 
Another old I.h. Letter slf 70-32 dated aug 14,1970
modulator valve has been redesigned and is not interchangeable with the old due to a change that had to be made to the rear adapter casting to provide clearance for the new modulator valve body. The new modulator valve uses a shorter push rod having a length of 2.93 inches. (it does not give the length of the old one)
new IH part no. Description old I.h. Part #
420153-c1 valve modulator 381978-c1
420154-c1 rod, push modulator valve 381979-c1
 
If a long, 3.44" pushrod is mismatched with a short modulator, then I think it makes sense that the shift points are way too high.

To allow upshifts at part-throttle, the engine's manifold vacuum is used pull the pushrod out the backside of the transmission. When the pushrod is too long, then you've fooled the transmission's governor into thinking that you've got the throttle wide open.

Eventually, the governor will override the modulator and force an upshift, but you've got to pick up lots of speed....as you've experienced.
 
So which modulator do I need? It looks like my orginal transmission had the newer version. This trans. Has the old one.thanks

thinking a bit, I May need to just adjust the modulator on the trans. Because of the trans. Going from the v8 to the v6.

Btw, I did not switch the rods, but what if I put the short rod in the long (original) valve?
 
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Sounds like you need the long modulator since you've got the long, 3.44" pushrod.

modulator381978c1_225270.jpg


If you're already using a long pushrod with the long modulator, then have you checked to make sure that the modulator diaphragm is holding vacuum? If the diaphragm is broken inside, then you'll have the same shifting problem because vacuum won't be able to pull the diaphragm and pushrod back to allow an upshift.

Long modulators aren't that easy to find anymore. You might be able to use the short one from your old transmission, as long as you use the old transmission's short, 2.93" pushrod with it.
 
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I won't bet money that it's a modulator problem, but it's probably the 1st place to start looking whenever a transmission won't shift right because it's on the outside Of the transmission. Even if I didn't suspect the modulator, it would still be the 1st thing I'd look into, just to cross it off of the list before opening up the pan and spilling atf all over the driveway.

Given your transmission's symptoms, I think you're on the right track, though. In the end, you May be forced to open up the pan anyway to be sure that the pushrod is actually seated properly. It's not always that easy to stab the rod into the right position.

Are you aware that the modulator has an adjustment screw inside? I don't recall which direction to turn it, but it's inside the vacuum opening and it changes the tension on the diaphragm return spring. The information is in another post in this forum:

http://www.forums.IHPartsAmerica.com/transmission-tech/2277-borg-warner-11-aka-t-39-vacuum-modulator.html

cci06092009_00000.jpg
 
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Slf70-43 dated 10/21/1970-I knew that these old service letters would come in handy someday.
Turn the screw in a clockwise direction to increase pressure or in a counterclockwise direction to decrease line pressure. After each adjustment is made, it will be necessary to replace the vacuum line on the unit and recheck the line pressure.
To perform a line pressure check, connect a tachometer to the engine. Remove the 1/8 inch pipe plug located on the left side of the case near the front of the transmisson. Install a pressure gauge line connector at this point and place a gauge inside of the vehicle.
Operate the vehicle until the engine heat indicator reaches the normal operating temperature, at which time the trans should also be at or near operating temp. Then move the selector lever in "d" (drive) position. Apply hand and service brake and accelerate the engine to the recommended rpm shown in the earlier post. At this time check the reading on the pressure gauge. For correct pressure refer to the earlier post.
Control pressure 75-95 psi
for a 6-232 r.p.m. Would be 1200
for a v-304 with a t-39 in a Scout it list 1300 r.p.m.
For a v304 with a t-49 thans in a (d-line vehicle) 1000 r.p.m.

Warning.
It should be noted that pressure below the specified minumum value will endanger transmisson life.
For best shift quality adjust to the lower limit.
For best life in severe service, adjust to the upper pressure limit.
If you can give me the part # off of the transmisson I can look it up and tell you if you have a t-39 or a t-49.
 
Got a new modulator valve...still no second gear...I can manually shift it and it will go into second, but that's the only way....if I start out in drive and when it needs to go to second, I tach it up reaal high, it will go into drive and miss second gear altogether..
 
I'm no transmission guy, but it sounds like the front band isn't applying. Since it works when the shift lever is in the "2" position, then the band must not be broken. By the same reasoning, the front servo (a hydraulic cylinder that operates the band) is probably Ok too .... But don't release it from suspicion since that's a pretty common failure mode.

My guess, though, is that you're losing hydraulic pressure to the front servo in "d" for some reason. Hopefully, a dirty/sticking valve body is all that's wrong with it. Someone on this board cleaned up their borg valve body a couple of years ago and posted pictures. I'll try to dig up a link....if somebody else doesn't beat me to it.
 
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