42RH / A500 : No Second Gear After Rebuild

[MattyMo]

Hello,

I just finished rebuilding an A500 or 42RH for a 1995 Dodge Dakota 3.9L 4x4. I have done many transmissions before so this aint my first rodeo. Never had a problem until this time.

After the rebuild, I noticed that the transmission wont shift into 2nd gear. Both bands are adjusted to the proper spec. I hooked up a pressure gauge to the governor test port and the gauge DOES increase pressure as vehicle speed increases, meaning the issue is not a governor issue.

If I go fast enough it will shift into third gear, and reverse and 1st work fine too. I also cannot shift into manual 2nd but manual 1st works.

Any ideas?? Thanks in advance!

 

[fishy68]

The front band is solely responsible for second gear so the problem is in that area. When you rebuilt it did you air pressure test the servo to see if the band was applying? I always air pressure test everything to make sure it's working before I install it in the vehicle. If you didn't air test it I'd do that first. If it air tests ok the problem is in the valve body.

 

[AJ/FormS]

Yup, Air pressure test.
It is possible to set the band with the strut or anchor not properly located,and then have the strut flip out after an application or two. It's nice when this happen during the air-test, and not where you are now at. If the airtest proves the circuit is good then look to the VB. If the airtest seems to indicate a lazy application, look to the servo seals.
If you need to get into the VB; look for a stuck gov plug,a backwards installed shift valve or a wrong spring, or a missing/broken accumulator.
Good luck.

 

[MattyMo]

Hey Guys,

I appreciate the comments!

I went to look at it earlier today and I realized that I forgot to hook up the throttle valve cable. Whoops! Bozo move. Hooked it up and it shifts perfectly now!

 

[AJ/FormS]

It shoulda worked without it, just shifting very early. I suspect your line pressure is low, or the ratio of line pressure to governor pressure is out.

 

[MattyMo]

Hmm. I'm going to drive it for awhile and see how it preforms. If I feel like the shifts are late or off I'll drop the pan and Re adjust the line pressure.

The manual says gov. Pressure should be 1 psi per mph. My readings did seem to be slightly less than that. Maybe a few psi less. Didn't think that was significant. I don't think the tires are stock size so the speedo might be off a little.

Yeah I was confused about why this worked too. It doesn't make sense. But there was a clear difference when hooking it up. The only thing that makes sense is if the lever was always in "max throttle" position, meaning the shifts world be very late. Perhaps what I thought was third gear was actually 2nd. (I had the spring on the lever, but not the cable)

 

[RustyRatRod]

Maybe it was shifting SO early you didn't feel the shift to second. Almost like skipping second altogether. I've seen some do that.

 

[fishy68]

Maybe it was shifting SO early you didn't feel the shift to second. Almost like skipping second altogether. I've seen some do that.

I've seen that too

 

[TrailBeast]

Maybe it was shifting SO early you didn't feel the shift to second. Almost like skipping second altogether. I've seen some do that.

I've seen that too

Probably was.