What causes TH400 to shift slow?

[243]

The tranny in my 79 shifts slow and it's almost not noticeable when it does upshift.

Is this a sign of a pending rebuild?

Could it be the modulator?

Are there bands to adjust on the TH400 and will they cause slippage?

BTW, there is a loud clunk each time I shift from N to D or N to R, I suspect it's a u-joint(s) but have not had time to check.



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243

Ol'e Blue 79 Wagoneer 401/T400/QT
Red 75 Wagoneer (project)
Mean Green 76 Wagoneer (parts car)
99 Dodge Ram TD

cummins_isb@hotmail.com

[River Beast]

Could be a sign for a rebuild.... I opted for a shift kit when mine started to do the same.... haven't had a problem for 3 years now... the HD shift kit worked great for me, not saying it will work for you ... but it's a cheaper option to try before sinking $$$ in a rebuild.

As for the clunking between gears... could be the joints...or could be slop in the QT chain. there is a check hole on the bottom slope of the QT unit. All tension must be removed from the drivetrain to properly check the chain. You should not have more than 1" of play in the chain.

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Todd
"River Beast" (http://home.earthlink.net/~tjnkk)
http://home.earthlink.net/~riverbeast/rbthnl.jpg
14" of total Lift on 39.5" Swampers
44's locked with 4.89's
...and other stuff...
My Original FSJ site (http://www.geocities.com/spazz4life)
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"When approaching an intersection, remember...
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'93 3/4 ton 4x4 Suburban...a.k.a. "FSJ Hauler"

[jeepbob]

Is it shifting late or just real smooth? Does it slip between shifts?
The T400 are a very smooth shifting tranny stock (they don't call turboslushamatics for nuthin!) but can be made to shift firm with a shift kit. The bands are not adjustable so the best you can do for cheap is to change the fluid and filter. If your tranny is hige mileage then I would rebuild it at the time I put a kit in. I used a TCI hipo transpack in mine with the kevlar clutches and the full shift kit and that baby will give you whiplash when it shifts.

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65 wag. 360/edelbrock rb4/t400/20 t-case/4:10 d27/d44 broken power lok/onboard air/onboard 110v power(no inverter)/1999 Lincoln t.c.leather buckets/Lincoln ctr console/winch/33x12.50/tunes/water proof door pads
soon to have new motor/d44frt/d60r(4:10)welded diff/custom bumpers
see ya in da mud

[243]

Thanks for reminding me to check the QT chain. I've started driving it to work so I need to check it soon.

It shifts slow normally. It seems to slip between 2-3 with a lot of throttle but I try not to run it that way much. The Jeep and the 401 are pretty old and I want keep it together for a while.

I've changed the fluid and filter and was thinking about a shift kit myself. I want quick and firm shifts...

but not like the TH350 I had in my Nova. I had a B&M kit in the Nova and it would chirp third at about 75.

A local M&P tranny shop with about eight shops in Houston quoted me 400.00 for a full rebuild not including hard parts which may be worn. Sounds reasonable if they pull the tranny.

243

[Snakeyes_Tx]

Best kit for the buck Superior Shift Stage II. Cost is about 30 bucks at a place called PTP Transmission off of I-45. I can get you an exact address by tomorrow.

Rebuild is reasonable costing, but I've got a friend at the dealership I used to work for who could do it for about 100 bucks. You bring him the tranny and the parts he needs, and he'll take care of the rest.

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http://www.virtue.nu/yazahx/rand/sig.jpg

Snakeyes_Tx
86 J-20 "The Rusty Dinosaur"
360/727/208/44HD/60 <- 2nd of all of them.
"If you don't know what the numbers mean, you don't need to be here!"

[Red78j10]

I have locking hubs with the QT trnasfer and I have noticed that when I have the hubs Unlocked and the E-drive ingaged that it shifts alot harder from park to R to N to D and so forth. But when I have everything normal (hubs locked and e-drvie disingaged)it shift between gears smooth as silk. I am not sure if you are having to run your QT like i am because you clutch cones are F***ed.
AS far as it shifting slow I would call or stop by a tranny shop and explain to them what it is doing, maybe it might be something you can fix youself and save some bucks.

[243]

To be honest, I don't know if the E-drive is engaged or not. The switch is not turned to E-drive and I doubt there is even vacuum to the line.

Does this guarantee that I'm not running in E-drive?

I can turn some pretty tight circles, almost full lock without the truck jumping around or otherwise indicating that it's locked.



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243

Ol'e Blue
79 Wagoneer 401/T400/QT

http://www.0hassleisp.com/dwilk/79sig2.jpg

Red 75 Wagoneer (project)
Mean Green 76 Wagoneer (parts car)
99 Dodge Ram TD

cummins_isb@hotmail.com

[Red78j10]

Dependes, if you have locking hubs. if the hubs are unlocked and you are in e-drive you wouldn't fell any difference. IF the hub are locked you would fell a small jerking back a forth in the steering wheel when you made a sharp turn. but that is one way you can tell.