Engine/Transmission (1998.5 - 2002) shift firmness

[BJMarshall]

I have a 2001 4x4 with 150000 miles on it. 3. 54 gears and stock tires. Transmission was replaced by the dealer approx 55000 ago. I have only recently added a Smarty as the only power adder. I am more than satisfied with the power now. My full throttle shifts are firm and quick as they should be. Part throttle shifts (half or less) became slippery when the Smarty was added. They were so-so before. They were soft before, but the extra power at part throttle seems to be a bit much.

I set about solving this problem myself. The only "kit" I could find was the transgo kit. When I worked at a shop as a tech years ago, my boss had several heated discussions with Gil about his products and I haven't used one since.

I got several parts from Sonnax. I installed the billet piston, 4 ring accumulator piston, and the switch valve. I also turned the pressure up a little while I was in there. I wasn't sure how far I could go. I'm at 62 idle warm and 138 full throttle. There is very little pressure variation between the ports and all shifts including lockup are good except for the 1-2 shift. It is still a little soft under part throttle. All shifts are perfect at full throttle. I have played with the cable some and I seem to wind up where I started as the shifts get erratic if I go too far one way or the other.

I have been in the pan several times and there are no signs of metal or clutch material. The bands are adjusted properly and I have added a different band strut. The band seems to be in real good shape as well. You can still see the machine marks on the hub and the band is an as-new color.

For now all I would like to do is firm up the 1-2 shift a little. I plan to get the transmission done in the future, but I really see no need at this point.

When I spoke to Stefan Kondolay on the phone, he recommended a valve body for now, but I hate to spend the money if I am going to do the whole thing once the transmission fails anyway. Any help would be greatly appreciated.

 

[fox]

The valvebody it one part of a complete trans, so I don't see an issue getting it built in steps.

By the way, I have some experience with the trans-go kits, and did that ti mine. It is ok, but took quite a bit of time getting it where I wanted it. This is a lot of fluid loss.

I built a trans for a friend, using ALL DTT parts including VB, and the difference in shift quality is big. His is solid, accurate. Mine is not there yet. It is ok but there is a lot of diference. Wish I had gone that way, and if I drop the vb again, it will be a DTT vb going back in.

As far as your 1-2 shift, you can either drill the hole just a little or get a tighter converter. The latter is what I'd do.

Set the throttle cable so it move with the throttle, no slack.

 

[BILLVO]

check out BD's web site they have a pressure lock that will give more pressure at lower throttle. I notice there are a couple for sale on the cassifieds here too. it all mounts externally. sounds like this is what could work for your situation.

 

[BJMarshall]

A new converter is in the long range plan as well. I don't tow much and when I do it's not real heavy. Usually less than 10k. The high stall of the factory converter is very annoying, but I'm sure it helps the transmission live.

Adjusting the cable along with the other changes, have netted me a fairly decent shift.

I know what you mean about opening it up to make adjustments. It's a shame it can't be done without pulling the pan. I put a drain plug in mine so that helps some.

I don't know which hole to drill and I'm leary of experimenting. I guess I'll just wait until I can do the whole thing.

 

[BJMarshall]

I'll check out the BD part.

Thanks

 

[zstroken]

BD pressure lock is for lock up only. Replace the spring in the 1-2 accumulator with a firmer spring or restrict the orifice out of the 1-2 accumulator. I have seen people put in a solid piece of aluminum instead of the spring, but it is too harsh.

 

[BJMarshall]

I thought about blocking the 1-2 accumulator, but I was afraid it would be too harsh as you said. It looks like a valve spring would probably work there. I may try that and see how it does. Any suggestions on a spring? Where is the orifice you are talking about restricting? Is it on the valve body where the spring rests?

 

[zstroken]

The Orifice is in the case in the accumulator bore. Don't block it just restrict it. A spring that would work would be the blue one off of one of the pistons. I forget which one

 

[BJMarshall]

Thanks. I'm going to experiment with some different springs before I restrict the accumulator feed. I see where it is now. Shouldn't be hard to restrict. I think I have some drillable plugs that will work from the accumulator orifice on a 700. I hope swapping springs will give me what I want as it is pretty easy and you don't have to completely drop the valve body. Getting that e-clip back on the park rod can be a pain.

 

[BJMarshall]

Different springs didn't make much difference, but taking the accumulator spring out completely did. It shifts pretty good now. It will still slide the 1-2 shift with the Smarty on 7 or 9 between 1/2 and 3/4 throttle.