thook

Howdy folks,

As the title says, tranny is jerking into gear when shifting from park to R and to D. As well, it jerks when shifting while driving...but, only at first. After having driven her a for a bit, it smooths out a lot. Also, I've noticed a liquid swooshing sound coming from under the shifter/console area after starting her up....obviously from the tranny, but it doesn't happen a lot. Plenty of fluid in her and doesn't smell burned or look discolored. My first intuition is a solenoid issue and have even read it's most likely that. But, on the same article it also said the tranny could be behaving in this manner in response to an actual electronic engine malfunction; eg. coolant sensor, AFM, etc. Well, I do have a lean code flashing and haven't been able to track that problem down for atleast a year. And, the code went away over the winter and has only recently come back. I've checked all related sensors and checked for vac leaks to best of my ability with the lean code. Ideally, a smoke machine could track down that quickly, but no one around here has one.

Anyway, anyone around here familiar with the A/T's on these vehicle? I can diagnose engine stuff, but trannies are beyond me. The O/D light flashes a "normal" code, btw.

Thanks!

Flash319

Older autos tend to do this. Try changing oil and filter but i have never had luck. These trans also are affected by the engine temperature. They will not lock the converter until warm and also seam to hold gears longer when cold. Ths may cause the hard shift feeling. Somewhat normal since the idea is to bring everything up to temperature.

thook

Perhaps the hard shifting is compounded when it's cold, but it's never shifted this hard when cold before. Otherwise, I'd say normal, too. Maybe it is time for a tranny flush. It's been a long time and I frequently haul a heavy trailer with it.

thook

Anymore input would be welcomed. Thanks!

thook

I believe I've narrowed this down to a problem with the torque converter. Haven't tried testing the stall speed, yet. Right now just trying to source a good TC and I've found two options....both I have quality questions about. One offered at rockauto.com...a dacco. The other from O'reilly...a pro-king. Anyone ever used either of these brands? Is there a better to be had for not much more? I use this vehicle to haul a trailer 2-3 times a month with a lot of weight, so I do want something that will hold up.

Thanks!!!

Flash319

If you are sure its the TC i would go get one out of the wreckers. I built automated machines for making TC (welding them together) and they are finicky to make. I would not trust non OEM.

space-junk

iTrader: (1)

i second that.Get an OEM one, or if you could, find a shop thatll take a look at yours. Also, thook, you prolly already know this, but the FSM tells you how to check the stall.

rustypigeon

When you say the transmission is "jerking" are you saying that it has a hard shift condition? If that is the case, your problem is likely caused by high line pressure. High line pressure is the result of an incorrect throttle cable adjustment, faulty primary regulator valve, or faulty accumulator piston.

Page AT-15 of this link has the throttle cable adjustment procedure...
http://htftp.offroadsz.com/marinhake.../5prelimin.pdf

It would not be the solenoids based on your description because a solenoid malfunction would not affect reverse. A vacuum leak would not affect this transmission directly as it does not use vacuum to control anything.

If by "jerking" you are saying that it is shuddering in all gears, then the torque converter would be suspect.

thook

well, i thought i was sure it was the tc. then, i made a call to an old friend of mine i hadn't talked to in years. he's been working on tran's all his life and is now the manager at fayetteville transmission. long story short, he explained how the whole system worked and from his years of experience ruled out the tc in the first 30sec's of conversation. he narrowed it down to most likely seals and clutches. but, that would be determined by taking a sample of drained atf...which i did just 30min's ago. nothing in the fluid!! no flecks of metal or "pepper" (as he used the analogy). but, the fluid really needs changing. using synth fluid, a tranny cooler, and a remote aux. filter i think may have saved my ars on this. this is the original trans and it's never been overhauled after over 230k. which, from his experience, is atleast twice as long as he normally sees them last before needing servicing. probably reflects more on how many people take care of their a/t's. anyway, it may not rule out the valve body, though. whatever that it is. i've not gotten than far in my ect a/t education, yet.

so, before i finally got my friend on the phone, i did source a very reputable tc/brand. "precision" is the name. a shop out of van buren has used them for over 30 yrs without issue. so, i know where i'm gonna go if/when in the future i need one.

thook

thanks, junk! yes...i've already found two great a/t tc threads in my search for a good tc unit. one has some good instruction on checking the stall. as well, i found the very info on autoshop101.com looking up how to test the solenoids.

thook

i don't know what the reg valve or accu' piston is, yet. is the reg valve the same thing as the "valve body"?

by jerking i mean when it does go into gear it's a big jolt. but, it takes a minute or so before it will...unless i rev it (while moving, of course) thereby forcing it to shift. again, by the time it warms, it smooths out and stops jerking into gear. my friend said it sounded like to him a condition of low pressure until the fluid could warm and circulate causing the seals to seal better and then it's able to build up enough pressure to shift. but, like i said above, i don't see any signs of seal deterioration in the fluid sample.

thanks for the adjustment link. i wonder if that will help with the sluggish acceleration at all? i've been told in the past it could affect it.

thook

i just called my friend down at the transmission shop, again. he said it still could be the valve body, o-rings, solenoid, or something. granted, he also said it's hard to diagnose over the phone. so, meh....i suppose i'll see what happens. it's $2400 for the overhaul. $400 of that includes labor of removing the tranny and reinstalling....which i can do all that. customarily, though, he said it's good if they can do that part so they can verify it's function once installed and address any potential issues after the install.

now, rustypigeon....you said it wouldn't be solenoids because that wouldn't affect reverse. also, you said it could be high line pressure (i'll adjust the throttle cable), reg valve, or accumulator piston. could the latter two malfunctioning be relieved by a fluid change? iow's, could it potentially allow me to drive the vehicle until warmer weather? before when i'd checked the fluid, it looked cleaner on the stick. but, when i actually took a drain sample from the plug it looked dirty. but, not bad dirty and still didn't smell burned. meh... i should have checked underneath months ago, but just didn't think to do it that way.

lastly, could oil leaking from the rear engine seal be affecting anything like on a clutch/manual trans situation? i have leakage from the back of the motor where the tranny mates and from where the transfer case joins and at the transfer case drain pan. not sure if the leakage at the motor is oil or a/t fluid, though. it was cold and dark when i checked a/t fluid from the transmission last night, so didn't check. i will today, though.

rustypigeon

-The solenoids are not used for reverse. Both solenoids are off and the manual shift valve controls reverse.

-Based on your initial description, it sounded like high line pressure. I am still not quite sure I am understanding the transmission symptoms correctly. Did you say it takes up to a minute from the time you select D or R until the gear actually engages? If that is the case, it sounds like a stuck valve in the valve body. Just like your friend said it was tough the diagnose over the phone, it is even tougher to diagnose when reading someones description over the internet. What one guy calls a shudder, another guy might call slipping, vibration. jerking, hard shifting etc.

-A leaking rear main engine seal would not directly affect transmission shifting.

It would not be a bad idea to pull the transmission pan and inspect for wear particles. This will tell you if your clutches are falling apart.

thook

re: solenoids....yes, i'm understanding now what they are and how they work. had a conversation with a friend at a nearby shop while his son was welding the exhaust manifold crack on my suby.

re: symptoms.....okay, sorry...i'll lay it out clear as i can once more.
with vehicle/engine cold, then started, and then running
1) when shifting from P to R, there is a jolt. then from R, thru N, to D...it jolts again when D is engaged. there is no delay in engagement when manually shifting from one gear to the next. just the jolt
2) vehicle's now in D. acceleration is normal (albeit sluggish), but upshifting is delayed from 1st to 2nd. and, when it does upshift there is the jolt once the next gear is engaged. and, then from 2nd to 3rd it will jolt, also, but not quite hard
3) once operating temp is reached after driving a few minutes, the upshifting smooths out considerably to what should be normal
4) and, after driving around and then parking for a period of time, it will start jerking into gear, again....until it warms up, again.

after having talked to you guys and others, and then some thinking and more describing, it's sounding like a fluid circulation issue. yes/no? you mentioned dropping the pan, but i took a drain sample like i said. my friend at the tranny shop said that should indicate particulates/damage upon inspecting the fluid. i took the sample into a small glass jar and then shined a flashlight up through the bottom (like when candling my chickens eggs). there was nothing floating around or even settled at the bottom of the jar. just some dirty-ish looking fluid. nevertheless, i already plan to pull the tranny pan and t/c pan, clean the tranny screen, and put a new filter element in the aux. filter. then refill with some synth fluid with the addition of some lucas my friend at the nearby shop recommended. he's used it more than once with good results. then, i will change out the aux. element within short intervals the try and filter any crap in the torque converter.

rustypigeon

That sounds like high line pressure.

The transmission uses fluid from the pump to engage clutch packs and move valves. When this pressure it too high, you get harsh shifting as the pressure slams the clutch pack into engagement. High line pressure also robs power from the engine as energy is wasted to overcome the extra drag of the oil pump. When the line pressure is too low, you get slipping. The primary regulator valve controls this pressure.

If you didn't do the check in the link I provided above, do it now. That cable connects to the throttle valve cam in the valve body. If the stopper is 0-1mm from the boot as in the illustration, disconnect the cable and check to see that it springs back into position.

If that checks fine I would suspect a stuck throttle valve or stuck primary regulator valve. These valves can get stuck from debris or a "step" being worn into the valve body casting. Having the line pressure checked would confirm this diagnosis.

thook

i'll be checking it next week after i've gotten some fresh fluid to do a change. it won't be driven until then. it's time for a motor oil change and drive line lube, as well.

thank you, rustypigeon. it's much appreciated.

space-junk

iTrader: (1)

Might as well have a transgo shift kit installed in it while you're there. 100 bucks. and the people who've installed it, from what I read, absolutely love it.

thook

i'm not sure i understand what they're for. how would it benefit? i did a little reading on them, but it seems more of a performance related item. i only use the runner to pull a trailer, haul bigger/heavier loads that won't fit in my subaru, as a back up driver, and if we absolutely must get out in snow. plus, i just dumped a bunch of money on some r/r work for the suby. if i could convince my wife...whom the runner belongs to...it would a grand idea, perhaps down the road when savings have built back up. what can you tell me about it for my type of situation?

thook

ah, wait a minute...i found this: http://www.importperformancetrans.co...ications.shtml

so far, it's sounding like a pretty good idea. hmmmm......damn you! hehehe....

space-junk

iTrader: (1)

http://www.transgo.com/products.php?category_id=149&parent_id=45&product_ id=254

not all the fancy words, but does the same thing. like I said, if the trans is being rebuilt anyways...hahaha.