I've now had my new-to-me 98 Auto for a week or two. I now feel that from what I've learned from this wonderful site that NOW I can ask an intelligent question. My question is with my 47RE tranny. A liitle updating first....I have added flowmaster 4"stainless exhaust. Bumped the timing to 15.5*. I also added a magnatech tranny pan too. I already had a boost & pyro gauges. Next week I will install the tranny temp sensor in the hot side of the tranny line. After the new pan I have added 10qts of cheap tranny fluid ATF +4. (I plan on doing Amsoil next week with temp gauge install) The old fluid was so so in color and did not smell especially burnt or anything.....just old.

Now for the question....the shifting seems kinda not-so brisk. If I floor the accelerator, I don't get the 1...2...3...4...L/U. I get 1..2......3.........4..L/U. BUT, I noticed yesterday after driving to the coast (2 hour mountain drive) that if I mashed the accelerator, I got a nice crisp shift pattern. 1..2..3..4..L/U. Why would (likely) very warm fluid equal a significantly better shift pattern?

I also want to point out that the poorer shift manners were the same before the new tranny and 10 qts of fluid. The only difference I can tell is that long drive and probably warmer/hotter fluid.....


Tom

 

23 lookers, but no ideas??????

 

how about the throttle position sw??

 

My truck does that too. I spoke with Dave at Goerend Bros and he thought it sounded backward. The hotter the tranny the better it shifts. That would say it isn't viscosity related. The only reason I can think of is thermal expansion.

I was testing my torque converter lockup and found out the clutches are about fried. After a warm day, it was locking up much better but still with some slippage. The heat must be expanding the components so they fit just a little tighter.

Your tranny is new to you or your truck?

 

Mine also did that before i put in the transgo shift kit. The shift kit helped firm the shifts,and helped the converter hold a LOT. It also made the shift quit hanging like they used to. The 3k GSK also helped too. Get a GSK, and either a valve body or cheap transgo like i got($50 buy it now on ebay) and you will think you have a new truck/tranny. It will be much more driveable.

Eric

 

Thanks guys for the ideas.....

The transgo shift kit WILL BE DONE. I've heard from a couple of other folks that it really made a positive difference.

The question about the miles on the tranny--Chasd60--What I mean is that I just bought the truck a week ago.

A developement........I have figured out what someone did to this truck. After inspecting some odd wireing and doing some hours of research, I found something out. The previous owner had a BD Pressure Loc system on my truck. I hope that doesn't mean a poor future ahead for me..... The system pretty much adds 30% more valve pressure for the T/C. It also shifts earlier. I also now understand that he had a three way type switch. That would have let him lock the T/C in 2nd or 3rd too. The break switch he had would have disengauged the T/C when he either lifted up on the accelerator or slowed to below 20mph....Oh well.

I think the transgo shift kit is simular. I REALLY don't like the late shifting....

Tom