Archived 47RH Problems Help!

[Cummins4Life]

I'm posting this for a friend who needs help

My 47RH transmission will not shift, it has reverse, and what seams to be low gear, but could be second, im not sure. It will drive fine, no noises, I had NO prior problems in weeks past with the transmission doing anything, it has shifted great with no issues. I rebuilt at 95,000 miles, I have 120,000 miles on it now, there have been NO problems with the transmission the past 25,000 miles. when I put the gearshift into manual (1,2), and I drop it from 2nd to 1st it acts like it downshifts (A bump), but when I upshift from 1st to 2nd manually it doesnt seam to change. Im getting 20mph in at whatever gear its in at 2000rpm.

The truck sat on a lift for the last week or so while he worked on the truck but nothing he did involved the transmission. Its a 94 4x4. Transmission is "built" with a TST valve body kit and a Dunrite tripple disc TC.



Any ideas would be much appreciated.

 

[fox]

Have you tried to rev it to 3,000 rpm?

May be that it will skip 2nd and go to 3 rd.

If this is it , check the front band adjustment. Maybe it broke, thus no 2 nd gear.

 

[Joe G.]

Check your pressures. That sounds like the governor is stuck. The governor pressure should be about 1 PSI per MPH. That is, at 10 MPH you should see about 10 PSI on the governor test port. Reving it to 3K is not a good idea until your know if your pressures are ok. There is a little valve (about $6) in the governor that can wear and mess things up.

 

[Cummins4Life]

Thanks for the quick replies guys. Where is the governer located in the RH? I thought there was one on the valve body but isnt there another in the overdrive unit?



Which port should he check pressures from?

 

[Joe G.]

There is no governor in the valve body of a 47RH. It is a fly weight governor in the rear part of the OD unit. The picture below shows the test ports. The upper image is the passenger side.

 

[Joe G.]

The first check that should be made is the governor test port. If the pressure does not change with MPH then you have something wrong with the governor. I'll scan a few more pictures and upload those so you can see what it is.

 

[Cummins4Life]

Thanks for the info Joe. He really appreciates it.

 

[Joe G.]

Here is an exploded diagram of the governor unit. The little valve near the bottom may be worn out and leaking. That could cause the symptoms he has.



The next picture shows the governor at the rear of the OD gear train. The OD unit can be R & R without pulling the transmission, but it is a PITA to put back. If you don't have a '94 or '95 service manual don't mess with it.



If the governor pressure is ok, let me know and we will see what else we can think of that might be wrong.

 

[Joe G.]

when I put the gearshift into manual (1,2), and I drop it from 2nd to 1st it acts like it downshifts (A bump)

One quick comment about the "bump". Manual 1st is different than automatic 1st so if you started in "2" and downshifted to "1" it changed from automatic 1st to manual 1st thus the bump. It was probably in 1st all the time.

 

[Cummins4Life]

Called dunrite, they say they are pretty sure that it is the govenor, they said to check the pressure, the bump im feeling is the lower belt, if this is the case, im going to just replace the whole govener. Give Thanks to the guys at TDR for helping out too. -Jordan

So thats where its at today. Thanks guys.