Transmission Question

[dschallmo98expo]

I have a 98 Expo with a 4R100 Transmission just rebuilt.

I have a question on shifting.

I have driven it for 3 days now and the the truck shifts fine except that the shifting pattern to me does not seem right. from 1st to second at normal acceleration sifts at about 2500 rpm. second to third 3700 rpm. third to forth almost immediately, and 4th to overdrive once I have gotten over 45 mph.

I feel there is a shifting issue here. am I right?

 

[stamp11127]

I would say so. How is reverse?

 

[1955moose]

As far as my 4r100, theirs only 4 total. Do you have a 5 speed, I've never heard of? It sounds pretty close on the soft throttle shifts. You can ask your trans shop what pressure they set up the shift points. My old aod's were about 33psi. These transmission are electronic so could be diff. I'll check my soft throttle shifts on the way home from the lake tonight.


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[docraymund]

You may have a faulty transmission control switch. You may not notice it but the trans may only be shifting up to third gear only. 4th gear is the overdrive gear.

 

[dschallmo98expo]

i thought it was a 4 speed with OD. Because I see the rpm change and feel it shift 5 times.

I will have them check.

 

[reece146]

The fifth shift you feel is the torque converter locking up.

< no, you're not going crazy >

 

[jchop307]

Sorry to thread derail, but does the the 4r100 have a different shift strategy when its cold? I only notice this when its extremely cold, otherwise its shifts perfect.

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[IMINYOURCHAIR]

How is it shifting at wide open throttle. should be smooth at about 4500 revs. and on my expy it had a habit of not locking up the torque converter until the trans and engine were at a certain temperature but before it had warmed up fully. it burns more fuel and makes more heat to get up to temp quicker.

 

[1955moose]

Last night going home here in San Francisco, I lightly throttled to see at what rpm it up shifted. It was basicly at 2200 rpm. I was real easy on throttle. It is 3 gears with od.


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[jchop307]

How is it shifting at wide open throttle. should be smooth at about 4500 revs. and on my expy it had a habit of not locking up the torque converter until the trans and engine were at a certain temperature but before it had warmed up fully. it burns more fuel and makes more heat to get up to temp quicker.

Thanks for the help but honestly I don't know, i never push it that hard. But it shifts perfect when its warmer and it doesn't do it when i let warm up longer.

I changed the fluid last year and it still looks great , so i figured Ford had programmed there to be a different strategy when its cold. So does it lockout overdrive or just not lock the torque converter.

My parents bought the car new and even though they had it for 16 years they dont know if it used to shift like that for them.

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