So I just got done installing a tf3 kit in a valve body I had. Put it in the trans along with an eBay special "super servo" and an hd front band strut... The servo seemed to fit pretty snug in the bore.. enough that I was questioning if it moved free enough...the trans is slow to engage into reverse and low and requires some rpms which would point to the stooooopid servo sticking. But when I drove the car it would not upshift? Any thought's?
need some trans help..tf3 won't upshift
- Thread starter SB75SM
- Start date
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fishy68
Tyr Fryr's Inc.
Which servo, Front or rear? If it's the rear servo and it's sticking that will cause it to engage into reverse slow but wont' affect it upshifting unless it doesn't release properly. If the front servo is hanging up it will cause no upshift. Neither servo will cause it to be slow engaging into first. The rear servo is active in low but it's not needed for low gear. It's just there so the sprague doesn't have to take all the grunt. The front servo gives you 2nd gear when it's applied.
By your description it sounds more like a low hydraulic pressure problem.
IMO: any time you install a servo you need to air pressure test it to see if it works properly.
By your description it sounds more like a low hydraulic pressure problem.
IMO: any time you install a servo you need to air pressure test it to see if it works properly.
KickDown
Just a Brit in Germany
Not just that Fishy. Every time I pull a valve body i do an air pressure test. Oh yeah, Is the TF-3 not a pure manual shift kit? TransGo say it allows you to convert back to automatic shift.
fishy68
Tyr Fryr's Inc.
I haven't done a tf-3 kit but it's my understanding that it converts it to full manual shift. I think their point is you can reverse it and put it back to auto shift as opposed to some kits that require major mods that can't be reversed. If you've air pressure checked it the problem must be low pressure or something not installed right in the VB. Do you have a pressure gauge to do some pressure checks with?
fishy68
Tyr Fryr's Inc.
First thing I'd do is run a pressure test on it and see what the line pressure is. Are you positive everything was modded correctly when the valve body was done? If the line pressure tests low I'd pull the valve body back apart and check it against the installation instructions very closely. You could also check the rear servo then.
BTW: I assume this was a good working trans. to begin with?
BTW: I assume this was a good working trans. to begin with?
fishy68
Tyr Fryr's Inc.
If it worked good before it must be something with the valve body then.
BTW: do you have a way to scan and e-mail the TF-3 instructions? If so I could look it over and maybe give you an idea where to look. If you can scan and e-mail it PM me
BTW: do you have a way to scan and e-mail the TF-3 instructions? If so I could look it over and maybe give you an idea where to look. If you can scan and e-mail it PM me
awesome man i really appreciate the help. will do as soon as i can. the sheets they send are pretty big so i will see what i can do to condense.
TrailBeast
AKA Mopars4us on Youtube
Don't forget the governor might just be stuck. (just in case you don't see a problem with the VB)
Tracy, if the gov sticks and keeps it from shifting I can't remember if engine braking is present or not.
Tracy, if the gov sticks and keeps it from shifting I can't remember if engine braking is present or not.
fishy68
Tyr Fryr's Inc.
This is a manual valve body kit he put in Greg so I'm not sure if the governor would affect it. I haven't done a Tf-3 so I'm not sure what's all involved. I'm not positive about the engine braking when a governor sticks but I'd think it would.
,,,,,,,,The governor has nothing to do with the up shifts as the port is blocked with a plug when u use the tf-3 kit.......u say it wont up shift but what gear does it start off in when in 2nd or 3rd, will it down shift when taking off in a higher gear and u shift down a gear......r u sure that whoever did the kit fully understood the instructions......what year is the kit, trans and valve body...I have did and use many tf-3 kits...kim......
Woods74
Broke Senior
I haven't had any luck with my 70 valve body with the tf-2, they were non part throttle kickdown before 71'. To me, it feels real sloppy, don't respond to throttle modulation or TV adjustments at all, and doesn't shift right in general, others can back me up on this. I highly recommend getting your hands on a later one, or go manual.
fishy68
Tyr Fryr's Inc.
I have installed the TF-2 kit in pre 71 valve bodies with no problems. In fact I have a 69 VB in my Cuda now and it works fine except naturally it has no part throttle kick down but it doesn't bother me since my 408 has an abundance of torque. One issue I ran into a long time ago is not to grind down the throttle valve as far as they say or some don't want to kick down like they should. In a case like PoisonDart describes I wonder if there's maybe just wear in the VB casting and of valves causing issues. Being 70 valve bodies are 44 yrs. old it's a possibility
SB75 since your kit is the TF-3 kit that converts it to a manual valve body I wouldn't think it'd make much difference which year VB you use.
SB75 since your kit is the TF-3 kit that converts it to a manual valve body I wouldn't think it'd make much difference which year VB you use.
I tire into the valve body last night and the line pressure valve felt a little sticky when I pulled it out but then I put it back in and it was fine...I do think that the transmission I pulled it out of had a very hard life...when I yanked the vb I found the accumulator spring broken in two
fishy68
Tyr Fryr's Inc.
It's a good possibility a little piece of debris had it jammed open. That'd cause exactly what it was doing. I'd take the entire valve body apart and give it a good cleaning and check over and lube the valves with atf when assembling it. Of course if you find any scored/worn valves it might be time to try that other valve body you have
Thinking I should look at that other vb I have....this is the bore of the line pressure valve
Oh and another dumb question...how does the tf3 run full line pressure so I don't have to run kickdown..
Local guy mentioned a cheetah reverse manual, am I correct that these do not have low band apply
Oh and another dumb question...how does the tf3 run full line pressure so I don't have to run kickdown..
Local guy mentioned a cheetah reverse manual, am I correct that these do not have low band apply
Lonewolf3165
Living the Dream!
Fishy gives good advice & insight here. I'd venture to say he's probably done a few more of these over the years than I have. If I could just throw my 2c in. FWIW I had a 727 that gave me very similar problems after a VB & servo modification & it turned out to be leaking servo. I fixed that & it worked fine afterwards. Air pressure test is what found it. Good luck. HTH.
Woods74
Broke Senior
^Yup, fishy is the man, and he's correct on my case being the old worn out valve body causing issues. Some have harder lives than others, let know how it goes!
fishy68
Tyr Fryr's Inc.
That doesn't look too good but I'm not sure that'd cause such a severe problem like you have. How does the valve itself look? Lets go back to the rear servo issue you mentioned. Did you air pressure test it to see if it's working? Something else that stands out is you said it starts off in 2nd gear. That tells me the front band is activated but why is a mystery at this point?? Not sure on kickdown linkage. The only reason I can think they'd retain it is to soften the shifts at lower speeds. You can try tying it back and see what happens.
I believe your correct that the Cheetah has no low band apply. If your interested in a manual shift VB with low band apply take a look at what Cope Racing has to offer. A&A might have something also.
TrailBeast
AKA Mopars4us on Youtube
Cracked or leaking accumulator would do it, but it would probably be dragging a clutchpack at the same time.
LocuMob
Fluid Technician
My buddy had a similar problem. It was a warped valve body that was letting fluid get by and apply the reverse band. Car didn't want to go. It was like we tied an anchor to the bumper. New valve body with the same mods as the old one, presto, went like a raped ape. Hope you get it figured out.
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