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Fingers crossed on the car and while I'm sorry you couldn't get the original back to form, you got a replacement transmission and kept a great piece of machinery on the road. Boston will now be better off. This has still been a fantastic read for us.
Things are progressing well for my wife although there are still more hospital visits to come so long as Corona virus does not screw things up which is possible.
I suspect the valve body in my original transmission could be the culprit. If the torque converter was bad it would not cause the clutch slippage at low revs.
The clutches are not being compressed with fluid when gears are selected. They were when I did the external pressure test with compressed air.
So either that or one or more new solenoids are no good.
I would love to be able to "play around" with these issues but way too much work without a lift.
The "new" unit was a lucky break and not much more than a refurbished valve body and way less than a new one.
Actually not done yet as I have had a problem with both the pump seal in the transmission and the rear crankshaft seal.
I suspect the transmission pump seal could have been damaged when the trans was taken out of the original car if someone took the torque converter off. In any case it was leaking quite badly.
I had a spare one so replaced that.
Also the rear crank shaft seal that I replaced leaked badly. The first one that I bought I think was quite old and the "flexibl skirt" just was no longer flexible and did not create an adequate seal with the end of the crankshaft. It had no spring in it at all just the "skirt".
The second one that I bought, orange in color, did have such a spring and does create a tight seal.
Good job I used Mercon Sp as I was able to easily see that I had two completely different leaks.
See these pics:
I have almost everything back in place. I am doing some exhaust work and waiting for a couple of "narrow band" clamps.
When the exhaust is finished will do another trans fluid top off.
Just drove the Jag off the ramps and up the drive no issues so far.
However, there has to be something right, I tried flashing the ECU a couple of days ago and it failed.
It ran thru testing and started the flash and ran for about 8 minutes or so then stated "cannot communicate with ECU" or something similar and also stated that the vid block was not written.
Quite a while ago i got a similar failure to read the ECU with my iCarsoft and just put it down to an issue with that device.
Yet to take the car for a drive or even think about doing the adaptations.
First few miles just cruising then when I accelerated up to 70 mph onto a highway with traffic threw check engine lite and also restricted performance light came on.
That was at about the 5 mile point. Drove another 15 miles with two relatively hard acceleration runs up to lets just say a speed under a 100 mph with no traffic around which came up nice a quickly each time. In other words the car accelerated like it used to with no apparent issues.
Used my iCarsoft to look at codes and I am lean on both banks so I have an air leak somewhere.
First few miles just cruising then when I accelerated up to 70 mph onto a highway with traffic threw check engine lite and also restricted performance light came on.
That was at about the 5 mile point. Drove another 15 miles with two relatively hard acceleration runs up to lets just say a speed under a 100 mph with no traffic around which came up nice a quickly each time. In other words the car accelerated like it used to with no apparent issues.
Used my iCarsoft to look at codes and I am lean on both banks so I have an air leak somewhere.
No DTCs for the transmission tho.
Such a pleasure to drive this car!
Hello John im wondering where did you purchase the used transmission from? Also I’m wondering if the transmission you rebuilt had valve body issues? I read your write up, it is very good and detailed.
Hello John im wondering where did you purchase the used transmission from? Also I’m wondering if the transmission you rebuilt had valve body issues? I read your write up, it is very good and detailed.
I bought it on Ebay.
I had been looking on Ebay for a while for a low mileage suitable candidate and at the time I was considering a new valve body it came up.
My next step was going to be the valve body
I strongly suspect that it was the valve body and or a solenoid even tho the solenoids were new.
If I were to put the valve body/TCM that is in the working transmission in my car now into that rebuilt transmission I would bet that it would work.
I had been looking on Ebay for a while for a low mileage suitable candidate and at the time I was considering a new valve body it came up.
My next step was going to be the valve body
I strongly suspect that it was the valve body and or a solenoid even tho the solenoids were new.
If I were to put the valve body/TCM that is in the working transmission in my car now into that rebuilt transmission I would bet that it would work.
Way too much work to do that right now.
Thanks for the reply. I’m willing to bet it’s the valve body as well. Solenoids were new, had to be separator plate or leaking valve. I’m VERY curious to know that information. After your very intense rebuild, I was in suspense reading it and following along. Or it could be the piston seals in the transmission as well. I don’t know. Anyways Thanks for the reply again
Thanks for the reply. I’m willing to bet it’s the valve body as well. Solenoids were new, had to be separator plate or leaking valve. I’m VERY curious to know that information. After your very intense rebuild, I was in suspense reading it and following along. Or it could be the piston seals in the transmission as well. I don’t know. Anyways Thanks for the reply again
I did not replace the piston seals, as you know, however when I did the "air test" the clutch plates in the drums all moved the way they were supposed to.
Anyway I have a spare transmission that I think would be fine if I rebuilt the valve body which after reviewing many videos I think I could do.
It is on my to do list for some day.
The first thing I would do would be to try the old valve body in my "new" transmission . If it then failed I would know the valve body is no good.
I did not replace the piston seals, as you know, however when I did the "air test" the clutch plates in the drums all moved the way they were supposed to.
Anyway I have a spare transmission that I think would be fine if I rebuilt the valve body which after reviewing many videos I think I could do.
It is on my to do list for some day.
The first thing I would do would be to try the old valve body in my "new" transmission . If it then failed I would know the valve body is no good.
That is not so much work.
That’s a very good idea. I’d love to hear what happened after installing the valve body. I’m thinking about doing a rebuild on my own. I really didn’t see any special tools. Like stand for tranny. I think it’s not really needed. What do you think? Also where did you buy your rebuild kit for the transmission? Sorry for all the questions but your write up inspires me. I’ve been a mechanic 20 years and counting beverage thought about really rebuilding a transmission myself. I’d really like to give it my all.
That is how the rebuild kit is listed with the period at the beginning on Ebay.
I made two significant mistakes during my rebuild process:
1. Mixed up clutch plates and drums when disassembled.
2. Did not measure the free movement space when clutches were compressed in drums in original state before disassembly.
You mentioned free movement space in drums. Of course you would be comparing the measurements against what’s supposed to be in spec right? When you say clutch plates you are referring to the steel plates right? I’m just making sure I am following you correctly. When I attempt this I want to feel comfortable. I read on the ATSG website somewhere when rebuilding a zf6hp26 the clutch packs are suppose to be a bit loose. They didn’t really get specific on that. My thing is with the transmission you rebuild yourself it’s doing the exact same thing it was doing previously. I really believe that was a good rebuild. I can’t see it behaving the same way even if the clutches are packed a bit tighter in the drums. It would of been good if you had of measured them maybe it would of shed some light. I’m excited to rebuild my own. Thanks for the info on the kit. You are a huge help! If the solenoids are new in valve body I’m definitely wondering what could it be exactly.