Jump to content

Shift Issue


Monteman1971

Recommended Posts

I have a 454 with a turbo 400. Under normal driving conditions the trans shift properly but at WOT it won't shift from 1st to 2nd without letting off the gas and then stomping it again? I changed the vacuum module but after reading about it, it only effects the trans under normal driving and does not play a part at WOT because there is no vacuum at that time........

 

Any help would be appreciated.....

 

Thanks,

Steve

Link to comment
Share on other sites

Got no answer to your question, but---I see you've got your latest photo. Love the new hood. I saw the pics of the hood during prime/paint.

 

Carl

Link to comment
Share on other sites

Sounds like an issue with the governor. I played around a lot trying to get the perfect shift points and with some combos of springs and weights it would shift exactly like that. I would have to let off fo it to shift. If it was the switch the tranny would not downshift.

Link to comment
Share on other sites

The down shift switch is working because under normal driving conditions, if I step down it does down shift. My problem is up shifting from 1st to 2nd....it doesn't want to.

 

Mike, of all things, transmissions are a mystery to me...it's that magical thing under the car that changes gears.....lol. Now I do have skills but is messing with the "governor" something that I can attempt on my own or is it something I should leave to a pro? And if so, does the transmission have to come out? I would hope not being that it sounds like you had to make more than one attempt to get yours where you wanted it.... smile

 

Carl, I just posted some new pictures in the "General" forum that show the hood better.

 

Thanks,

Steve

Link to comment
Share on other sites

Steve, the tranny does not have to come out to service the governor. It is under the little square cover with the round top on the side of the tranny. If you can get one out of another th400 you can swap it and see if it fixes your problem. 20 min to change.

Link to comment
Share on other sites

Steve have you changed the rear axle / ratio ? If so the govenor may not be sending the shift signal. As Mike57 says sounds like the govenor . If you have a local tranny shop that will work with you thats a good choice . I find my local shops dont like to talk .:( Good Luck .

Link to comment
Share on other sites

Guest Phils72

Hey guys I am somewhat new to the club, but maybe I can shed a little light on tranny troubles. I build automatics for a living, and build HP trannys for local racers. The problem sounds like you have to little govenor pressure. This is a common problem on TH 350 & 400's. Even if it has been built, most rebuilders do not check the govenor bore in the case. Most of the time they need to be sleeved in order to have the right specs from case bore to govenor. One thing to check, is to take the 4 bolts out that holds the govenor plate on. you will loss a little fluild not much, but have something to catch it. After pulling the plate, remove the govenor. Check for deep lines on the govoner shaft. If you can feel the lines with your finger nail, good chance it's worn. If you have a transmission parts house near call and get a new gov. This may help closen the specs enough to fix the problem. If not it needs to be sleeved.If I can help you get the parts you need let me know I will do what ever I can to help a club member.

 

Phil

Link to comment
Share on other sites

Thanks Phil.....I'm going to look into that. Is there a gasket that will need to be repalced? Will it come with the new govenor? The tranny was a fresh rebuild before I got the car but I really don't know what was done.

 

I don't think so but can the adjustment on the vacuum modulator be effecting this at all? The weather has been pretty bad here so I haven't been able to test much. On the module should it be turned in or out for performance shifts?

 

Thanks again and welcome to the club!!!!!!!!!!

Steve

Link to comment
Share on other sites

Guest Phils72

You will need to get another gasket, I doubt it will come with the gov. As far as the modulator, it's purpose is for part throttle upshifts and your downshifts. At wot modulator pressure is bypassed, so all you are working with is gov pressure. If the tranny is shifting early or late, at part throttle (Normal driving)then you can adjust the modulator to help with that. If you can't find a new gov and gasket, call me and I cane get you one and send it to you. 704-460-6456 leave message if I don't answer.

 

Phil

 

P.S. Your car looks great. Where can I find fiberglass fenders?

Link to comment
Share on other sites

  • 2 weeks later...
Guest XXXXXXX

Phil, Great to have you onboard! And a transmission expert to boot! Two questions, when sleeving the gov. bore does the bore need to be enlarged and if not can a sleeve be installed with the trans in place? Thanks.

Link to comment
Share on other sites

Guest Phils72

Yes, you will have to bore the case over size. The only problem is the tool to do this is pretty high. Because of the metal shavings this will cause. it is best to have it out and torn down, but I have done it with the tranny out of the car and stood up on the output shaft with the rear housing off, it's not easy but it can be done. The good news is the sleeve now comes prbored to fit a new gov, so you don't have to cut the sleeve to size. Hope this helps.

 

Phil

Link to comment
Share on other sites

Guest XXXXXXX

Yes,big help. My trans is showing some signs of age and I'll have to have it rebuilt at some point. I watched an episode on Muscle Car about auto trans rebuilds and the host mentioned to look for play in the gov. bore but not that it could be sleeved nor to look for grooves in the bore. Thanks again!

Link to comment
Share on other sites

Hey Phil,

 

My fenders and hood are steel but there are a couple of places that make them. I don't suggest "Bodyworks" if you come across their stuff. It's all very ruff.

 

With my engine out I haven't had a chance to really look into my trans but i will as soon as I'm up and running...

 

Steve

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...