Calling all 700R4 Experts!

[mister.freeze]

No actual changes. Still no 4th gear.
While I agree, proper geometry is ideal, this has worked FOR YEARS as is. I'm trying to find out A) what causes a loss of just 4th gear and B) if it's something I can live with given my driving habits or do I need to start investing in a new transmission?
Might anybody know if there's an Allison that is a direct replacement for the 700R4?

[kwmech]

You'll need to get off the tangent that "It worked for years". Yes it did, but not correctly by your own admission, and now you're having problems. YOU WILL BURN UP THE TRANS (if you haven't already) by not correcting the linkage and making the torque convertor lock up. Not locked up they create an incredible about of heat that destroys clutches inside the convertor. Having an incorrectly adjusted TV cable will burn up clutch packs. Fix it right or have that trans rebuilt once again, rinse and repeat

[SeventyOne]

Get the TV cable geometry fixed.

You asked for "700r4 Experts" and here we are telling you what to do.

I even sent a link to exactly what you need.

[made2drag]

Originally Posted by mister.freeze

No actual changes. Still no 4th gear.
While I agree, proper geometry is ideal, this has worked FOR YEARS as is. I'm trying to find out A) what causes a loss of just 4th gear and B) if it's something I can live with given my driving habits or do I need to start investing in a new transmission?
Might anybody know if there's an Allison that is a direct replacement for the 700R4?

Ok, I know this is an old post and you recently got 4th back.

Things to check:

Have someone hold your gas pedal down all the way to the floor (not running) and feel how tight the TV cable is. If it's like almost as tight as a guitar string, it should be good.

While driving watch your speed around 50-55 and see if you see any rpm drops and if not, move from OD to D....do this like 10 times and you may see it shift. If it starts working it will probably keep working like mine did. Also, make sure your fluid is showing at the top of the operation mark on the dipstick, if it's even a hair lower than the crosshatching it may not ever shift into 4th. Check it after 30 mins of driving to make sure you get a good solid reading and if you add some, drive another 10 mins and check again.

A th350 low on fluid will not drive at all, a 700r4 will drive fine in 1,2,3.

Also, mine still wasn't shifting to 4th even with it hot after a 30 mins drive and showing on the full mark, until I did the OD to D shifts back and forth. I drove like 10 mins shifting it back and forth and it finally felt a shift.

I have 3.08 gears and a 26" tire and mine shifts at 17, 30 and 52 MPH.

Another rabbit to run is to make sure your dipstick is a stock 700r4 dipstick. I had a aftermarket dipstick in my last truck that gave me false readings for full. Not sure why people stick those Lokar dipsticks in....Junk.

[mister.freeze]

Originally Posted by made2drag

Ok, I know this is an old post and you recently got 4th back.

Things to check:

Have someone hold your gas pedal down all the way to the floor (not running) and feel how tight the TV cable is. If it's like almost as tight as a guitar string, it should be good.

While driving watch your speed around 50-55 and see if you see any rpm drops and if not, move from OD to D....do this like 10 times and you may see it shift. If it starts working it will probably keep working like mine did. Also, make sure your fluid is showing at the top of the operation mark on the dipstick, if it's even a hair lower than the crosshatching it may not ever shift into 4th. Check it after 30 mins of driving to make sure you get a good solid reading and if you add some, drive another 10 mins and check again.

A th350 low on fluid will not drive at all, a 700r4 will drive fine in 1,2,3.

Also, mine still wasn't shifting to 4th even with it hot after a 30 mins drive and showing on the full mark, until I did the OD to D shifts back and forth. I drove like 10 mins shifting it back and forth and it finally felt a shift.

I have 3.08 gears and a 26" tire and mine shifts at 17, 30 and 52 MPH.

Another rabbit to run is to make sure your dipstick is a stock 700r4 dipstick. I had a aftermarket dipstick in my last truck that gave me false readings for full. Not sure why people stick those Lokar dipsticks in....Junk.

YES!!! Practical experience!
The shifting in and out of 4 (OD) supports the sticky valve idea.
I currently shift at 16, 24. haven't driven enough to find a consistent upshift speed into 4th.
fluid level is correct.

[made2drag]

Originally Posted by mister.freeze

YES!!! Practical experience!
The shifting in and out of 4 (OD) supports the sticky valve idea.
I currently shift at 16, 24. haven't driven enough to find a consistent upshift speed into 4th.
fluid level is correct.

If you have big tires your actual speed will be slower on your guage, which is good, because all my reading says 1st to 2nd should happen between 17-20 and sooner shifts is bad for trans. Sounds like you might actually be shifting closer to 20 into 2nd and 30 into 3rd. Im using a gps unit that just plugs into my cig lighter to check my speeds.

I keep reading that after a rebuild 4th acts up but eventually works again. I know yours was working and recently quit so I don't know if that applies... I know lots of people wont believe it but that's what I keep reading. The other thing I read was driving til it shifts to 2nd then turn key off, then crank back up in neutral, then shift into OD again. Something about fluid movement but I cant remember now.