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Thread: 89 XR-7 - transmission won't shift

  1. #16
    Join Date
    May 2002
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    Quote Originally Posted by hulakai View Post
    So great to have so much input, thanks guys.
    .
    .
    I haven't been able to spend a ton of time on it the last couple of days, but I did a bunch of testing....drive, stop, adjust, drive, stop, adjust...and I was able to get it shifting up through all 4 gears at what I would call 'normal' shift points. However, the downshifting wasn't even close to right and I'm 99% sure it's because I don't have the right bushing on the throttle lever where the TV cable connects.

    Thanks again for the help. I'm glad there's still lots of guys on here. Can't wait to start working on my SC in the spring and do some fun things to it vs just trying to get this Cat driveable!
    Its not the bushing. The setting for the AOD TV cable is not that sensitive. I drove for 10 years with one attached with a twist-tie. and it worked perfectly fine. If its driveable, just drive it until it stops shifting.. BTW, AOD downshifts are just bad all over.. you need to almost floor it to get a downshift, so don't sweat that part. One tip: Try driving in "D" in town if you're generally driving 50 or slower. You'll be much happier.

  2. #17
    Join Date
    Jul 2005
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    427
    Good afternoon


    I believe the overall shifting issue could be reduced with the addition of @Lube Gard Red to the transmission fill. It is not transmission fix in a can (or bottle in this case) but if the valve body has varnish causing valves and pistons to stick this product address the issue. I would do a complete drain (including the torque converter), inspect and filter change with the Lube Gard additive. Do search on the reviews.


    http://www.lubegard.com/SearchByCate...id+Protectant#

  3. #18
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    Apr 2017
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    Quote Originally Posted by sam jones View Post
    Good afternoon


    I believe the overall shifting issue could be reduced with the addition of @Lube Gard Red to the transmission fill. It is not transmission fix in a can (or bottle in this case) but if the valve body has varnish causing valves and pistons to stick this product address the issue. I would do a complete drain (including the torque converter), inspect and filter change with the Lube Gard additive. Do search on the reviews.


    http://www.lubegard.com/SearchByCate...id+Protectant#

    Thanks for that....now I won't pull my hair out trying to get the downshifts perfect. I got a new bushing today but didn't get to working on the car. Tomorrow. I also thought the TV adjustment was super sensitive for something that attaches to a cheap plastic bushing, but there WERE very noticeable differences in the shift points with only a one or two notch adjustment. As you say though, downshifts seemed less affected.

    I also wondered about valves being sticky, especially if it was sitting without the proper amount of fluid in it. I'll definitely change the filter and fluid and put some additive in it, thanks.

    Question: How does one drain the fluid out of the torque converter without removing the transmission from the car? Hope that isn't a stupid question...it's been a while since I had a transmission out of a car, and from what I remember the only way to get fluid in or out of the converter was through the opening for the input shaft?

  4. #19
    Join Date
    Dec 2007
    Location
    Salem OR
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    Quote Originally Posted by hulakai View Post
    How does one drain the fluid out of the torque converter

    The TC should have a small drain plug, accessed thru the rubber cover lower front of the housing - spin the flywheel to locate. Add the diff fluid while the car is off the ground and you're waiting for the trans/TC to drain, unless it's still too cold to be underneath, as you said before. Let's hope that much fluid change doesn't cause issues.

  5. #20
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    Apr 2017
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    Quote Originally Posted by TbirdSCFan View Post
    Its not the bushing. The setting for the AOD TV cable is not that sensitive. I drove for 10 years with one attached with a twist-tie. and it worked perfectly fine. If its driveable, just drive it until it stops shifting.. BTW, AOD downshifts are just bad all over.. you need to almost floor it to get a downshift, so don't sweat that part. One tip: Try driving in "D" in town if you're generally driving 50 or slower. You'll be much happier.
    Got it...I've noticed that before too...that downshifts for something like passing requires you to almost floor it. The downshifts I was more concerned with were at slow speed i.e. slowing down then trying to accelerate but it's still in 3rd, or even 2nd if you're almost at a stop. Is THIS the kind of thing that will bake the transmission? I'm never been clear on exactly what condition a disconnected TV cable causes that would bake the trans.

  6. #21
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    Dec 2007
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    Salem OR
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    You're right about all those tiny notches...

    Note this link on AODs from B&M: http://files.dpbrands.com/bm/instructions/114501.pdf

    5. AOD transmissions are extremely sensitive to proper Throttle Valve linkage/cable adjustment. Proper adjustment of
    this linkage/cable is the most critical step of your installation. BE SURE TO CARE- FULLY READ THE INSTRUCTIONS IN THIS MANUAL THAT RELATE TO THIS ADJUSTMENT!


    See this thread for discussion:

    http://www.sccoa.com/forums/showthre...ble-Adjustment

    'baking' a trans, of course, means heat. The cable controls pump pressures. Pump pressures are used to tighten or release bands. A band that should be tight when it's loose will slip and generate heat. A band that's tight when it should be loose can force the drive train to power thru it, causing heat. It doesn't take long to fry a band, drum etc. in either case.
    Last edited by KMT; 12-09-2017 at 09:24 PM.

  7. #22
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    May 2002
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    Dallas, TX
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    Running a can of additive which will clean up the valve body, at this point, is a good idea. Certainly can't hurt. But do it before you change the fluid and filter.

    The issue with the disconnected TV cable is that is allows a drop of pressure overall, and results in more slippge+heat. Thats what bakes the friction plates, especially the frictions in the direct clutch. If it went on for a long time, you'd pretty much have to rebuild the trans. But you'd have worse issues from what you describe. There would noticable slippage, failure to upshift, etc.

    Overall, about as much as you can do is to attach, adjust, change fluid+filter and if its driving OK, live with it. Anything further requires a rebuild. I learned how to do that years ago, but theres a learning curve and to overcome the mistakes you'll make, you have to be prepared to remove and install a few times. If you've got the determination to take it on, buy the chilton book on AOD transmissions, at every car parts store, and good luck.

  8. #23
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    Apr 2017
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    Quote Originally Posted by TbirdSCFan View Post
    Running a can of additive which will clean up the valve body, at this point, is a good idea. Certainly can't hurt. But do it before you change the fluid and filter.

    The issue with the disconnected TV cable is that is allows a drop of pressure overall, and results in more slippge+heat. Thats what bakes the friction plates, especially the frictions in the direct clutch. If it went on for a long time, you'd pretty much have to rebuild the trans. But you'd have worse issues from what you describe. There would noticable slippage, failure to upshift, etc.

    Overall, about as much as you can do is to attach, adjust, change fluid+filter and if its driving OK, live with it. Anything further requires a rebuild. I learned how to do that years ago, but theres a learning curve and to overcome the mistakes you'll make, you have to be prepared to remove and install a few times. If you've got the determination to take it on, buy the chilton book on AOD transmissions, at every car parts store, and good luck.
    Engines I can build....transmissions I've always left for the pros.....too complex and expensive to risk a mistake.

    I'm starting to consider taking it to a tranny shop to get the fluid, filter, diff fluid change and TV adjustment done with the pressure gauge instead of me adjusting until it feels right. The adjustment doesn't scare me too much, but we just got our first blast of snow (I live near Buffalo if any of you were watching football on Sunday) and I REALLY don't feel like laying on a wet, cold garage floor trying to get 80/90 to drain from the diff and hoping I don't screw up gaskets because I'm trying to do it lying under the car. I guess I'm just getting old. Years ago I would have done it in a t-shirt! Lol

    We'll see....if I can get it shifting nicely maybe I'll put in the additive for the valve body and do the diff now because the shudder is pretty bad....am I doing damage or is the slip simply not working?

  9. #24
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    Apr 2017
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    Ontario, Canada
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    Hey all...

    I promised an update but it's been so damned cold here that I haven't worked on it much, but I DO have an update.

    I changed the fluid in the diff, and changed the fluid and filter in the tranny.

    I did NOT drain the fluid in the TC during this because I couldn't get the drain plug to break free! Ended up f'ing up the corners on the bolt after messing with it for so long and finally gave up.

    When I filled the tranny I put a couple bottles of Lucasoil additive in it, then I started messing with the TV adjustment.

    I finally got the adjustment to a point where it shifts through all 4 gears, at reasonable RPMs. However, it doesn't want to shift into 3rd when it's still cold. After it warms up fully it will shift.

    At this point I'm sure there is some wear/damage in the tranny or AT LEAST the throttle valve. It's driveable now which is great, but I don't think I've seen the end of this work.

    All I have is theories as to why it won't shift when it's cold, and those theories are a) sticky throttle valve, b) wear/damage in the tranny, or c) something wrong with the TV cable besides the adjustment.

    Thanks again for all the great information and suggestions here....and if anyone has any thoughts on troubleshooting the cold shift problem, I'm all ears (eyes?). Other than the cold shift problem, it runs nice and smooth at this point....oh, and no more shuddering. Turns out the shudder wasn't from the diff, it was from the tranny not downshifting at stops or near stops. The TV adjustment took care of that.


    On a completely unrelated note...I'll be looking to upgrade some things on my 92 SC in the spring, and I was wondering if anyone has found custom headlights....or made their own using the factory shells? I'm also going to be looking for some nice 18" rims....preferably black but if the price is right I'll get them powder-coated myself. Any suggestions on offset or where to find rims for a good price (used?) would be appreciated, either here or PM. I see Bill has some nice ones coming in...might just have to save my pennies for those because they're EXACTLY what I'm looking for.

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