Swap didn't go so well...05/06 XC70 engine and transmission

[VolvoDJ]

Hello again MVS people,

I've been working on an engine / transmission swap for the last year-plus (see viewtopic.php?p=601919#p601919 , viewtopic.php?p=637420#p637420 , and viewtopic.php?p=642369#p642369 for backstory) and FINALLY finished the swap. Too many competing projects and commitments to complete this any faster, and I had to work on it in fits and starts. It's really inefficient to do a project like this, btw. Thankfully, this was an extra car.

It worked GREAT...until it didn't. Started up on the first try, shifted into gear, made it out of the driveway and out on the road...and promptly entered limp mode.

Having MAJOR transmission issues now. Shifts into D with a BANG, but shifts into R smoothly. Shifts between gears just fine. Can drive it about 1/4 mile before I get a TCM-002B code (4th gear incorrect gear ratio) along with a P0700 (Transmission Control System Malfunction) and it drops into limp home mode with a big red warning of Transmission Serve Required.

I don't have VIDA, but my scanner (which covers all systems / modules) shows the aforementioned codes and will let me reset it and try again.

Fluid level is good, no burned smell. Haven't tried driving it in manual shift mode.

Any thoughts? Diagnostic pathways? Likely culprits? Things I may have missed? Or something I screwed up? Maybe it was damaged by the wreck?

What now? Should I pull the engine and trans back out, swap in the old transmission, and put it all back in? Get a rebuild kit and manual and rebuild the old old trans first?

Or should I just cut my losses and give up? Drive it off a cliff? (Probably not, I'd have to tow it there first...)

I'm frankly pretty discouraged. And tired. Feeling like a chump for trying something I probably shouldn't have. Stupid and stubborn, that's me.

Any advice would be most welcome. Thanks.

[dikidera]

Most people do not connect the PNP switch correctly is what I've noticed. It basically has a default hydraulic position for when you are assembling it.

Is this transmission your original or a replacement? It is entirely possible your replacement transmission is just as bad or worse than the old one.

[firstv70volvo]

Hello again MVS people,

I've been working on an engine / transmission swap for the last year-plus (see viewtopic.php?p=601919#p601919 , viewtopic.php?p=637420#p637420 , and viewtopic.php?p=642369#p642369 for backstory) and FINALLY finished the swap. Too many competing projects and commitments to complete this any faster, and I had to work on it in fits and starts. It's really inefficient to do a project like this, btw. Thankfully, this was an extra car.

It worked GREAT...until it didn't. Started up on the first try, shifted into gear, made it out of the driveway and out on the road...and promptly entered limp mode.

Having MAJOR transmission issues now. Shifts into D with a BANG, but shifts into R smoothly. Shifts between gears just fine. Can drive it about 1/4 mile before I get a TCM-002B code (4th gear incorrect gear ratio) along with a P0700 (Transmission Control System Malfunction) and it drops into limp home mode with a big red warning of Transmission Serve Required.

I don't have VIDA, but my scanner (which covers all systems / modules) shows the aforementioned codes and will let me reset it and try again.

Fluid level is good, no burned smell. Haven't tried driving it in manual shift mode.

Any thoughts? Diagnostic pathways? Likely culprits? Things I may have missed? Or something I screwed up? Maybe it was damaged by the wreck?

What now? Should I pull the engine and trans back out, swap in the old transmission, and put it all back in? Get a rebuild kit and manual and rebuild the old old trans first?

Or should I just cut my losses and give up? Drive it off a cliff? (Probably not, I'd have to tow it there first...)

I'm frankly pretty discouraged. And tired. Feeling like a chump for trying something I probably shouldn't have. Stupid and stubborn, that's me.

Any advice would be most welcome. Thanks.

Here's a video of this transmission being rebuilt, at 12:32 into the video is the 4-5 clutch and your 4th gear incorrect ratio code may be caused by this clutch slipping. One question I have is, if you do a reset and drive the car very easy and on level ground or slightly downhill and especially when shifting from the 3rd to 4th will the car drive a while without getting the incorrect gear ratio code? This would help determine if the 4-5 clutch is slipping. The bang into drive is typically due to a sticking linear solenoid or worn valve body. If you only had the bang into Drive I'd say you might get away with only replacing the valve body but this won't likely fix the 4th gear problem. If you're serious about rebuilding the original transmission watch the complete rebuild video and there's also another video for disassembly to see what it takes for the rebuild. I did rebuild my transmission, which was a first for me, and it's still going strong so it can be done but be prepared for a lot of work and it's not cheap if you do a complete rebuild, which includes a quality rebuild kit, the valve body, the converter and possibly case repair.
Also, how's the replacement engine, I probably wouldn't consider rebuilding the transmission unless the engine is in good shape too.

[VolvoDJ]

Most people do not connect the PNP switch correctly is what I've noticed. It basically has a default hydraulic position for when you are assembling it.

Is this transmission your original or a replacement? It is entirely possible your replacement transmission is just as bad or worse than the old one.

Thank you for the reply! This transmission and engine came out of a wrecked vehicle, and appears to be original to that vehicle. I did not disassemble the transmission or separate it from the engine, and unless inadvertently, don't believe I did anything to the PNP switch. I'll re-check all of the electrical connections in the hopes that something is loose.

[VolvoDJ]

@firstv70volvo--

Thank you for replying. I'll try that driving test the next time I get a chance. I fear, though, that the problem may be as you describe and require some major surgery.

Here's where things are right now. In the car I have a good engine, and the problematic transmission. Both came from a wrecked donor vehicle with ~110k miles on it.

On my garage floor I have the bad engine with a failed rod bearing that was removed from my car at ~159k miles. Attached to it is a transmission that was working fine when it was removed.

The "new" engine is pretty good by all indications. It runs smoothly and is throwing no codes, and I did a fair amount to it while it was awaiting install (timing belt, water pump, flame trap, exhaust gaskets, etc. I do have a MAF issue to track down, but it starts and runs well aside from that.

I'm tempted to take the engine and transmission back out, and mate the "old" transmission it to the "new" engine. I'm considering doing a rebuild on the "old" transmission before I do that, since it's easily accessible and I have some room to work on it. Or perhaps just refresh what is easily accessible and roll the dice on the rest? Not sure what that would be as I am not very experienced in transmission works but I can learn.

Any thoughts?

[firstv70volvo]

@firstv70volvo--

Thank you for replying. I'll try that driving test the next time I get a chance. I fear, though, that the problem may be as you describe and require some major surgery.

Here's where things are right now. In the car I have a good engine, and the problematic transmission. Both came from a wrecked donor vehicle with ~110k miles on it.

On my garage floor I have the bad engine with a failed rod bearing that was removed from my car at ~159k miles. Attached to it is a transmission that was working fine when it was removed.

The "new" engine is pretty good by all indications. It runs smoothly and is throwing no codes, and I did a fair amount to it while it was awaiting install (timing belt, water pump, flame trap, exhaust gaskets, etc. I do have a MAF issue to track down, but it starts and runs well aside from that.

I'm tempted to take the engine and transmission back out, and mate the "old" transmission it to the "new" engine. I'm considering doing a rebuild on the "old" transmission before I do that, since it's easily accessible and I have some room to work on it. Or perhaps just refresh what is easily accessible and roll the dice on the rest? Not sure what that would be as I am not very experienced in transmission works but I can learn.

Any thoughts?

If the transmission that came out of the car was taken care of and shifts goods now then you should just consider swapping out the transmission, you don't have to pull the engine but you will have to drop the subframe to swap transmissions. A rebuilt converter could be done before the swap.
Try the easy driving test with the bad transmission to see if the code pops up again right away or not. One thing I was thinking about is how the gear ratio is calculated, is the ratio checked with the converter locked up and if so could it be a problem with the converter locking up. When you test drive it again pay attention to the 3 to 4th shift and try to notice if there's any delay or slipping, during the shift and afterwards to help determine if it's the 4-5 clutch.

[VolvoDJ]

The transmission was working well before the engine failure. I've been watching the rebuild video you linked (and the associated teardown video) and I'm not sure I am up to that, lots of details to keep straight. But I'm tempted. I have a space where I could work on it, and I found the ATSG rebuild manual for it. When you rebuilt yours, did you use a manual? And which rebuild kit did you use?

Where would you source a rebuilt torque converter? When I first started this project I had planned to do that, but none of the businesses I found would sell to me as an individual. They would only sell to a shop, so I set that plan aside.

Would you recommend doing anything else before the swap? I have been looking at the procedure for just dropping the trans. I don't have a hoist, so I'm trying to figure out if I would have enough clearance to do that from below. I have some larger heavy-duty jack stands, perhaps 4 of those would do the trick.

Thanks again for your help.

[firstv70volvo]

The transmission was working well before the engine failure. I've been watching the rebuild video you linked (and the associated teardown video) and I'm not sure I am up to that, lots of details to keep straight. But I'm tempted. I have a space where I could work on it, and I found the ATSG rebuild manual for it. When you rebuilt yours, did you use a manual? And which rebuild kit did you use?

Where would you source a rebuilt torque converter? When I first started this project I had planned to do that, but none of the businesses I found would sell to me as an individual. They would only sell to a shop, so I set that plan aside.

Would you recommend doing anything else before the swap? I have been looking at the procedure for just dropping the trans. I don't have a hoist, so I'm trying to figure out if I would have enough clearance to do that from below. I have some larger heavy-duty jack stands, perhaps 4 of those would do the trick.

Thanks again for your help.

I used the ATSG manual and YouTube videos. The kit I got was this one
https://www.oregonperformancetransmissi ... SN-RB.html

Had to buy some tools but not many, a universal spring compressor, snap ring pliers, winch, clamp bars, metal parts to better support the engine, misc chain, botls, etc.

The converter was done at PDQ in Sacramento, very reasonable price and they did it in a day.
http://www.pdqparts.com/Map.shtml

I purchased some bushings here and this place also does case repairs for this transmission.
https://www.omegamachine.com/

Here's a photo of how far my car was raised to drop the subframe then transmission. I also don't have a hoist and improvised using a winch and a power drill to lower and raise the transmission. You can see the winch on the top support bar. The red rachet straps were used to support the steering rack, which was detached from the subframe.

Used a floor jack and 2x6 to lower the subframe.

[VolvoDJ]

Awesome. Thanks for all of this, especially the pictures.

Ingenious use of the square tubing to support the passenger side lift point! Is it just resting atop the engine support bar or did you anchor it in some way? Also a great idea to use the worm-drive winch instead of another jack to support the transmission.

I'm a bit far from Sacramento but will call PDQ after the holiday to see if they can help me out or recommend an alternative.

Again, thanks for your help.

[VolvoDJ]

Finally got the time to try the easy drive test. Failed in pretty much the same amount of time, but this time I get:

TCM-0020, transmission output speed sensor faulty signal

and

TCM-002A, third gear incorrect gear ratio.

So I didn't even get to 4th gear to see if that problem could be recreated

Looks like it's time to swap transmissions. Still haven't found a local shop to do a rebuilt torque converter, since it's the holidays a lot of places are shut down.

Any other advice or suggestions? Also chasing down an issue on (presumably) the intake side, won't stay started unless I keep it revved about 2000 for a minute or so, then settles into a very rough idle. Feeling a bit like throwing in the towel, if I'm being honest.