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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[1955moose]

Best thing you can do is find a friend or maybe a trans shop, take a ride in theirs and compare. Mine shifts the same points, hot, or cold. My only complaint is that it doesn't shift from overdrive, back to third, until about 33 mph. I would like it to do the 4-3 light downshift at about 41-44 mph, but it works so well, I don't dare touch it.


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[Yudaman]

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

Mine is a 4 speed with overdrive...
But mine doesn't shift until I push in the clutch and move the lever.

But as far as the auto shifting, sounds about right to me. You can buy a programmer and adjust the shifts points to your liking. I know that I wasn't overly impressed with the factory shift settings when I had the 4r100 in my 98.

 

[1955moose]

I was reading your original post again. Your 1-2 shift is about right, but the 2-3 is too high. Again my 4r100 shifts same point for both gear shifts. I'd find an experienced trans mechanic and find out problem. Shifting that high for 2-3 up shift can't be easy on the trans. It's possible they have too strong a spring in the valve body that's controlling that up shift, or a defective solenoid or switch. It's troubleshooting time.


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[dschallmo98expo]

no troubleshooting time for me. I spend 2k on getting the trany rebuilt. it goes back to them and I will not touch it again until its fixed. and I will not give them another dime. 2k is a fully complete rebuild including external electrical parts and valve body springs and any other thing that may be an issue. I hate it when any mechanic takes advantage of anyone or short cuts the repairs. Makes me fume!!!! in the end a lawyer usually fixes all issues!!! hah!!!!

 

[1955moose]

Wow dude, you need to calm down. People come on this site for advice on how to fix their SUV themselves, or to help them when they bring it back to their mechanic. Your problem is fixable by the trans guys, probably something simple like a shift solenoid. Were on your side here remember. Good luck!


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[IMINYOURCHAIR]

Best thing you can do is find a friend or maybe a trans shop, take a ride in theirs and compare. Mine shifts the same points, hot, or cold. My only complaint is that it doesn't shift from overdrive, back to third, until about 33 mph. I would like it to do the 4-3 light downshift at about 41-44 mph, but it works so well, I don't dare touch it.


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just push the o/d off button to get it to downshift when ever you're ready for it to.

@jchp307; 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.

it won't kill it to get down on it, may even blow some soot off of the cats and valves. but it will show if there is another problem like where it's holding a gear too long as was mentioned. if it goes through all the gears fine at wot to say.. 80 or 85 mph where it's safe to do so.

 

[dschallmo98expo]

I'm fine. just I come here to fix things on my own that I can and then get advice and direction for things that I cannot. its frustrating at times.

 

[jchop307]

@jchp307; 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.

it won't kill it to get down on it, may even blow some soot off of the cats and valves. but it will show if there is another problem like where it's holding a gear too long as was mentioned. if it goes through all the gears fine at wot to say.. 80 or 85 mph where it's safe to do so.[/quote]
Ok thanks ill give it a try, im gonna also let a good buddy of mine drive it and see what he thinks about it also. He's certified on transmissions, and he also owns a lightning with the 4r100 so he can compare it to his. Thanks again for the help

just push the o/d off button to get it to downshift when ever you're ready for it to.

@jchp307; 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.

it won't kill it to get down on it, may even blow some soot off of the cats and valves. but it will show if there is another problem like where it's holding a gear too long as was mentioned. if it goes through all the gears fine at wot to say.. 80 or 85 mph where it's safe to do so.

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