Band Adjustment 48re, New MM3 and other issues.

[CrewCabDiesel]

I added a MM3 last month and have a few issues (referring to my truck ). The motor power is awesome in sport mode it breaks the tires loose at a 30mph float, finally using all the toys I built into the Cummins with 8 years ago, see signature.
Transmission has about 20K miles on a rebuild and is out of warrenty.
I getting under the truck today to look for some probems, yesterday I found my 4X4 linkage broken off, thinking my new transmission mount got shreaded by the MM3 resulting in a bang and a shift (thought my leaf spring bushings are fried too) when I step on it.
Have drive line shudder with or without a load with more than light throttle.

I will be pulling the pan and installing a new shift solenoid and pressure sensor (upgrade from ATS) adjusting bands and of course new fluid and WIX filter

1st, Can a broken transmission mount break the 4X4 shift linkage? Mount looks ok, Im going to try jacking it up to see if there is a problem.

2nd I had the hard down shift when they rebuilt the transmission, could the trans shop have backed of the band adjustment to get rid of it?

3rd Been reading Factor service manual, TDR and youtube and band adjustment seems straight forward, use the correct tools, correct inch pound torque. back off the adjustment screw 1 3/4 turns and 3 turns. Am I missing something?
Please advise, Im open for suggestions and advice. Automatic transmissions scare the heck out on me, I build motors, and just about any other sysem on cars and trucks but transmissions are still scary.

Thanks Kyle

 

[Ozymandias]

Sounds good to me, only i never used a torque wrench for it. Finger thight with the wrench is about the same.

Little hint, for the jam nut of the front band come with the wrench from above, vertical. It is easy accessible that way.

 

[CrewCabDiesel]

Well the transmission mount, carrier bearing are good. Rear leaf spring bushings look dry rotted from what I can see. Going to hop in the old imperial a get a new bushing from Advance auto. And start with the front band adjustment and see how the works first.

 

[CrewCabDiesel]

Got the rear band adjusted, it was way off, no metal in the pan. Truck drives/ shifts better now, reverse works a lot better, less throttle to move the truck backwards.
Does anyone know how to adjust the kick down cable? Seems that the motor lugs down when the trans should downshift. Also increasing the adjustment on the down shift cable increase transmission oil pressure?
Thanks
Kyle

 

[Timd32]

Read thru this one and see if it fits your application. I've read that there are times the bracket might have to be tweaked a bit if needed at the Trans side, someone with some actual experience might provide some better info.

Transmission throttle valve cable (Fig. 228) adjustment is extremely important to proper operation. This adjustment positions the throttle valve, which controls shift speed, quality, and part-throttle downshift sensitivity.

If cable setting is too loose, early shifts and slippage between shifts may occur. If the setting is too tight, shifts may be delayed and part throttle downshifts may be very sensitive.

 

[CrewCabDiesel]

I have been reading bunch of different articles too, almost sounds like the adjustments are dependent on how you drive. I have always tended to be very light footed, especially with $5.19 diesel prices. Of course that can change with certain songs on the radio and stupid drivers

 

[Timd32]

Few years back I think it was a guy over on M73M was dialing in his adjustment with a home made pressure gauge in the truck, you can dial it in from what I have seen to shift at your desired RPM. Unfortunately the gauge let loose in the cab and made a complete mess out of the cab with fluid all over.

Having it unhooked will cause damage pretty quickly. I have always read the factory adjustment is pretty good.

 

[CrewCabDiesel]

here is a new one, took off the throttle cover, moved the throttle back and forth and the TV cable moved too! the clip holding the adjustment is gone! bothe the cable housing and internal cable are moving, the internal cable is moving more but it is way out of adjustment. Have a new TV Cable coming.

 

[Ozymandias]

DO NOT DRIVE the truck with that condition, you'll destroy the transmission super fast as the line pressure stays at idle value that way. It slips severely without you knowing it.

 

[CrewCabDiesel]

I used a screw to hold the adjustment in place until the new tv cable gets here. Shifts great now. I'm hoping the travel the tv cable still had kept the clutch packs and bands in good shape.
Going to send and oil sample for analysis to see how much material is in it.

 

[Timd32]

Have not seen an ATF report before, interesting. Guess it's all about the same.

 

[Ozymandias]

For adjustment of the TV cable, with a modified transmission you can possibly not adjust with the factory specs. You need to adjust it that it upshifts at 3000rpm WOT. The shift point is your spec.

 

[CrewCabDiesel]

Ok, got it shifting at 3100 rpms, solid shifts. When I built the motor is good to 5000 rpms, heavy valve springs and it's balanced.
I am sending an transmission oil sample in for analysis, I hope to post the results on this thread when I get it back.