TH 400 problem... or is it?

I need some help. I've had this problem for about 2 months now. Im not sure whats wrong with my TH 400 but I can discribe what its doing. I have a pretty steep driveway and normally I barely have to touch the pedal to back up it and it wont roll back down if i just let it idle without the break. Recently after I drive it for 15 or more minutes and I come home and then start it up again lets say 20 minutes later it has real trouble backing up the driveway and idle wont keep it at a standstill. The best way i can describe it is it feels like driving with the E brake on starting off the line (most noticiably on my driveway) but shifting and cruising and even punching it seem normal. I just got the trans cooling lines away from the headers and a flush with fresh oil (the old oil was burnt black, I guess from the lines touching the headers). It seemed to run better for a day and now its doing it again. My friend told the oil pump might be going out due to the heat but here's the catch. I was backing it up and down my drivway today trying to listen and feel what was wrong so I could better describe it to somone. The engine was hotter than normal but not at the middway mark and i got to the bottom of my driveway put it in N and revved it and then gave it some throttle in drive and reverse with the brake and it backed up like nothibng was wrong! I took it around the block came back and it started doing it again! :af: This dosent sound like the pump loosing pressure with temp to me because the engine was more than cruising temp when it just magically went away. This has happened 3 times now. Please help me figure this out.

 

It's slipping.......and you prolly burned your clutches by now. I hate to be the bearer of bad news, but it needs a rebuild. :bglasses:

 

Darn. Kinda expected that. Thats what i get for ignoring those lines that were touching the headers i guess. The problem is I just ordered a new centerlink and I'm having the lower ball joints replaced as soon as they get the parts in. It's gonna be 610 when all is said and done. Should have waited, but my parents were threatening to end the ensurance payments if I didnt get the horendus steering fixed. How much should I look to pay for a rebuild if it turns out i need one?

BTW thanks for replying and may I say your riv looks sweet :eek2:

 

I'll assume the Riv in the photo is yours.......that being said, you have a switch pitch TH400. Make sure you take it somewhere that knows what one is or else you will have endless headaches and it will never be right. You'd be surprised how many guys who have been in the business for a long time and are prolly good transmission mechanics who look at you like you're smoking some funny stuff when you tell them you have a 2 speed torque converter. Ask Brian (Rockstarr) he just went through it with his tranny.

I'd offer to do it for you but the shipping to NY from CA would be too much to make it worth it. Perhaps you should start a thread on this board and ask if anybody knows of a good tranny shop in your area. If you're gonna spend about $600 to fix it you may as well get it done right the first time. Many of these tranny shops think all TH400's are the same, and they're not. The SP400 is a different animal and to do it right requires at least knowing there's a special torque converter in there that uses a special front pump that has a solenoid in it. Does your car still have the switches on the throttle linkage? Do you know if they're working? If you can find a tranny guy who knows how they work and how to adjust them you'd prolly be the first guy on the planet who did. :bglasses:

 

Well thats funny because I thought I had a TH400 and my freinds dad, Chuck Edwall, who owns 3 of the most beutiful cars on the planet (1 was featured in hotrod). And he took a look and asked me what the thing coming off my throttle body was and I thought it was just the kickdown which I assume was standard on TH400. I told him that it might be a SP400, thanks to your other thread, but I didnt know. He thought it was weird and left it at that. Is there a way to tell beyond the switch on the throttle body? By the way its a 67 so the engine is a 430 not a nailhead. I just want to make sure before I go shooting my mouth off about it being a switch pitch and find out they didnt use the SP for the 430. Anyways he gave me the name of a shop (ill post the name when I get home today, starts with an H... Harold's?) that he goes to which he took his 56 olds (not the Hotrod featured car) and which has a rare trans that was only made for 1 year. The guy did a superb job according to him (2,000 dollars later OUCH!) so with luck he might know somthing of the SP400 as well. Im gonna give my mechanic a chance first as he always gives me great prices (because I think im his best customer :ball: ). And by chance I mean I'm gonna say its a switch pitch 400 and if he gives me a funny look and says there is no such thing its off to the other guy. The 600 I was refering to was the cost for the steering stuff I just ordered w/ labor for the ball joint replacement which puts me in the hole which is why I should have waited to do the steering and got to the bottom of the tranny problem first. If the price to fix the tranny gets to 600 though, should I consider buying TH400 level 1 replacment from trishield and install myself? http://www.trishieldperf.com/transmissions.htm
(Is the trans from them or do you send in your core and they rebuild it? Something about them not painting it because is alluminum confused me.)

I gotta go the cheapest route because my parents are gonna take the hit on this one and my Dad's about ready to make me garage "the money pit", and by a honda hybrid.he would sell it if it wasn't my Mom's old car... she won't let him :grin: .

Thanks for helping out a NewB.

 

Yes....'67 is the SP model, '68 and up were not. The way to tell is by the pan......if it's the original, it will have a kind of heelprint shape stamped in it. The later ones didn't have that and the pan and filter are different.

I've never used a trishield transmission myself, but I'd be inclined to think that's the best way to go. Whatever you do, don't let anybody install the wrong converter on yours.......or give you an "exchange" tranny that may not be a SP model. As far as I know the only way to get a new SP converter at the local tranny shop is if they send it out to be cut open and rebuilt. uzzled:

I would just have it flushed and use it over but there's a risk in doing that. As long as your old fluid didn't look like metallic paint I would think using it over would be OK. IMO it's better to know you have the right converter than pay for a new one of unknown quality that may not even be correct......perhaps someone who knows more about this can chime in here? Larry? Mark? o No:

 

OK, so I had quite an emotional rollercoaster ride with my car today. I took it to my mechanic about 2 hours ago right after school. He wasnt there right then so I started talking to the other mechanics who work for him and described the problem. I mentioned the clutches going out and they said I needed a rebuild. I said ok, thats what ive been told so how much would it cost. Get ready for this.
$1600 :jd: I just couldnt believe it. I was about ready to head over to get another estimate from the shop that was recommended to me when the owner showed up. He got in the car and started driving it with me riding and said he deffienitly couldnt feel any slipping and really couldnt feel the problem at all while we went up and down really steep hills. I could hear and feel the loss of power but he didnt have the normal behavior to compare it to. He said if there is a problem its not bad enough to need a rebuild yet. The only thing he mentioned was the mushy and somewhat premature shift from 1st to 2nd. When we came back he took the vacuum advance hose off while I gave it some throttle and slipped it back on and he seemed satisfied. The car seemed to go back to normal with the whole car torquing a bit putting it into gear with plenty of power at Idle. He got in, seemed to see the difference and we tried the steep hills again. By the time we got there it was screwed up again so he couldnt see the difference. I just told him to keep it overnight and try it in the morning as the first run of the day is always fine regardless of temperature. One thing I didnt mention earlier is the pinging im getting at higher RPMs recently, which Im hopefull might be related to this vaccuum advance thing that seemed to fix the problem for a second. Another thing I didn't mention was that if the engine is revved in Park to around 5500 and quickly released the rpms stop at about 1200 and it idles real chunky for about 5 seconds and then comes back down to 500 rpm. This too, only just started happening around the time I noticeed the power loss. One last thing I might mention is that in the upper RPMs (when its not pinging) with the problem It feels like it has more power than when it feels normal. IE when I floor it from around 40 with the problem it really launches when it kicks down, more so than when it feels normal at lower speeds. I hope this sounds like it might not have anything to do with the transmission at all but rather the timing and the untuned QJ I bought new from summit ( it wasnt tuned because when I installed it I put the vaccuum advance on the wrong outlet... i think, and when my mechanic tried to tune it after the engine rebuild he said it was broken so it never got properly tuned with the vaccuum hooked up properly). Hopefully I only need a $80 tune up :laugh: / :ball: ... I hope

If you have the time to read this long post let me know what you think.

BTW the flush yeilded no metal flakes or shavings so maybe it can't be to bad and if it is the trans I can reuse this transmission.

 

Well Im not sure if im running full or not and how would i tell? As to if the vacuum is working thats what he was checking when we came back from the first drive. He took the hose off the carb and said something about it not working becasue the carb wasnt sucking at idle. I reved to about 1500 and he put the hose back on and the engine changed pitch and felt smoother so he said it was fine. Right after that i noticed it was acting normal again and I tried to show him when it is working right/ feels right it should idle up to about 10 miles an hour without throttle, not just barely creep forward and should take hardly any gas to get up to cruizing speed. However it stopped acting normal shortly after. Maybe the vacuum stops working after its been driven a while and some throttle play without load gets it to start again somehow? So if its not the problem and not cutting out then it is working. As to if its set right i couldnt tell you.

 

Could it also be the high stall/low stall not working or sticking in low or high with the switch pitch converter i was made recently aware of. Let me describe the problem again in a more comparable way. The car feels like it has the parking brake on or like im pulling a trailer at low speeds but high speeds is acting fine except for the pinging when it gets warm (usually over 20 minutes of driving with lots O stop lights or traffic). And If it could be the SP converter is there somethign external that could be the problem? I just need to exhaust my options before I spend a lot on a rebuild.

 

This is comparativly good news. Larry, I read your other post early and thats where I got the idea that it might be a problem with the SP. Ill try that as soon as I get the car back. My mechanic just called and told me nothings wrong . He just cant feel it I guess and refuses to believe me, the daily driver of the car, that there is a deffinite difference. You dont have to drive the car daily to become sensitve to the problem anyways. The difference is pretty big if you can feel the car when its acting right in low speeds and compare, so maybe hes an idiot (he wanted 1600 to rebuild the tranny... and thought I'd pay it). I tried to discuss the variable high and low stall with him and I dont think he understands it becaue he kept saying theres only a problem if it gets stuck in high gear and wont manually downshift. Soooo Ill try your suggested diagnostic Larry. Hopefully its a faulty wire, switch or loose connection, which would explain why it works perfectly sometimes and mysteriously goes back to normal if I rev the engine in idle (making the engine torque around and maybe getting the connection back ). If its the solinoids in the converter or it turns out theres nothing wrong with the converter it looks like Ill be hunting for a cheap shop here in San Diego and hopefully wont have to rip it out and ship it to tri shield. Should I still be driving it if it turns out to be the converter and just go easy till I find a good shop?

Ive read all the posts about the SP 400 and how it works but Im still wondering exactly what low and high stall does to the transmission and for the power output. I know (or think I know) a high stall converter gives better launches but is not very streetable. Is this comparable?

 

Here's what to do to eliminate the SP as the problem........there should be a orange wire going to the switch on the carb. Unplug it, that will put the tranny in the low stall mode. It will also disable your kickdown (passing gear). Drive it around like that and see if it feels different. The idle should be rough and the car should have a tendency to creep. It would be harder to hold the car from moving with the brakes. If it feels the same this way with the wire removed, then your SP isn't working. High stall is most noticeable at idle, b/c it smooths it out a little, and the tendency to creep is less in high stall.

If you think it's working OK when you plug it back in, and you definitely feel a difference at idle, then that's good. But my bet is the switch on your throttle arm is out of whack (either stuck or just out of adjustment) and not letting the converter change it's pitch. In that case, you will need to adjust it. If you don't have a manual, I can try to help you.......it's a tricky thing set especially if the switch isn't working properly. You should be able to hear it click when you lightly touch the gas pedal with the key on and the motor not runnning. That's why many guys just connect a switch under the dash.......sometimes that's easier than trying to get the factory setup to work right. If you need my help let me know. :bglasses:

 

OK I just got the car back from getting the timing retarded to stop the knock (feels slower and I cant spin the tires like I used to when I floor it from 20 mph in 1st ). I just took a look over what you described to me and I think you hit the nail on the head (pardon the pun). The setup is its not quite like you described. The only orange wire dosesnt go to the transmission (what does that do?) and the ones that do both have lost their color but one may have been orange but I cant really tell. Also there are a pair of grey wires that run back to a mystery switch on a hinge on the throttle near the firewall where the return spring connects. The problem is no matter where the throttle is it wont push on the switch and engage it so it just sits there. I have no clue what it does. If you can tell me what that does that would be great. The good news is I think all I needed to do was turn the eyelet screw futher in so at Idle the kickdown is pulled a little further out. The problem now is finding a position where it can extend far enough at idle but kickdown when floored. The range of motion in the kickdown is too great for the throttle body on the carb. If theres anyway I can adjust this let me know.

Nailhead thanks for all the advice, I would still be pulling my hair out if not for you. The only problem Im finding is that when it feels right it acts like its in low stall at a stop and starting out. When it feels marshmellowy starting from a stop I assuming its in high stall. Idle and off idle dont seem to be changing this like you said they would. I figured this out by just taking the kickdown off and letting it rest on the manifold while i drive it, and pulling the kickdown all the way out (feels normal/ creeps but starting from stop feels good) and pushing it all the way in (no creep but it feels mushy from stop). Is it supposed to idle in high and switch to low as soon as you give it throttle?
Again thanks for all the help.

 

Thats exactly what it was Larry. Right after I posted I decided to give my 67 manual another look and found the detent switch and idle stator switch just like you posted. I didnt find it earlier becasue I had no clue what the names were. The stator switch just needed adjustment. So now it idles smooth takes off crisply. mmmmm feels so good. I dont think its ever worked and I just firgured the creep and the chunky idle was the RV cam and the drum brakes. Thanks for all the help guys. I have to go enjoy it now because its going into the shop tommarrow for the lower ball joints and centerlink and I'll be stuck with the terd (ie moms mini van) for the weekend.

Hey thanks for all the help guys! Would probably be getting quotes for a rebuild if it wasnt for you. BTW the cars black now so I gotta post some pictures for you.

 

I just got done scanning that page from the manual with the intention of posting it for you.......but by the time I got done screwing around with this SLOW computer I see you are already set. I'm glad you got it fixed! :TU:

I thought I'd post it anyhow in case anybody else needs it: ou:

 

Maybe someone can enlarge that for me? The bigger image is too large to send.

 

For future reference a really good trans shop in the San Diego area is WALTBILT'S in Oceanside. 1 760 722 7007. He has done three trans for me:200R4 five years ago and still works perfect, 96 Chevy truck recently and ten years ago a 66 Ford truck auto. A friend of mine has had over a hundred automatics done by him and has had only one need to be reworked. :TU: