2004 xc70 jerk shifting into reverse, with new valve body

[vtl]

To vtl, is the collar sleeve the splines part that mates the transmission and angle gear? Is it possible to inspect it without disassembling parts? Also is it going to worsen or become dangerous if ignored? I saw some instructions on angle gear collar replacement:
http://www.vpcuk.org/forums/showthread. ... -2004-S60R
looks pretty challenging.

You can turn propeller shaft CW/CCW and guesstimate how much play is there in worn splines, but you need to know how much of that play is in other parts, like transmission differential and CV joints. If the collar sleeve is still the original, it is safe to assume it has worn splines.

Stripping splines damages the splines on the input shaft of the angle gear. From there it will eat itself: each new collar sleeve will live shorter and shorter, and unlikely it will outlast more than 2 or 3 sleeves. Preventative measure is to replace the sleeve before it strips.

Also a harsh P-R gear switch can be attributed to a mechanical part of the transmission. It does somewhat wear the transmission, but if you keep changing ATF every so often, it will probably outlast the engine. I have not the best P-R (or D-R) switches for the last 140k miles, the transmission is still very driveable, with the Sonnax-rebuilt valve body.

The most important aspect affecting a long life is the quality of upshifts and downshifts. AW55 dies mostly of oil starvation when internal filter clogs up. Everything else this transmission can chew up and drive on, but low oil pressure is the end.

For your downshift jolt I'd verify with DiCE/VIDA what gear shift was it. Shifts around 3 is another mechanical wear, which can be more or less easily fixed/reduced.

[arrrxivvv]

To vtl, is the collar sleeve the splines part that mates the transmission and angle gear? Is it possible to inspect it without disassembling parts? Also is it going to worsen or become dangerous if ignored? I saw some instructions on angle gear collar replacement:
http://www.vpcuk.org/forums/showthread. ... -2004-S60R
looks pretty challenging.

You can turn propeller shaft CW/CCW and guesstimate how much play is there in worn splines, but you need to know how much of that play is in other parts, like transmission differential and CV joints. If the collar sleeve is still the original, it is safe to assume it has worn splines.

Stripping splines damages the splines on the input shaft of the angle gear. From there it will eat itself: each new collar sleeve will live shorter and shorter, and unlikely it will outlast more than 2 or 3 sleeves. Preventative measure is to replace the sleeve before it strips.

Also a harsh P-R gear switch can be attributed to a mechanical part of the transmission. It does somewhat wear the transmission, but if you keep changing ATF every so often, it will probably outlast the engine. I have not the best P-R (or D-R) switches for the last 140k miles, the transmission is still very driveable, with the Sonnax-rebuilt valve body.

The most important aspect affecting a long life is the quality of upshifts and downshifts. AW55 dies mostly of oil starvation when internal filter clogs up. Everything else this transmission can chew up and drive on, but low oil pressure is the end.

For your downshift jolt I'd verify with DiCE/VIDA what gear shift was it. Shifts around 3 is another mechanical wear, which can be more or less easily fixed/reduced.

Thanks for the advice, will check the angle gear sleeve. I don't drive this car much, so will probably put this off for a while. I'll report back when I have time to work on it.

[firstv70volvo]

I'm actually fine with how the car drives now, but concerned that since the valve body didn't cure these problems, it may be some more serious mechanical issues that can get worse or dangerous if I keep driving the car. If it's just a nuisance I may as well live with it, but I guess it's rarely the case when it comes to car problems.

I also have no experience with transmission repairs by professional shops. How much diagnostics can they do with the trans still on the car? I heard they can do some line pressure testing through some pressure taps. And if there is a mechanical problem, does the cost depend on how big the problem is, or as long as transmission need to come off and be taken apart it would pretty much cost the same?

Thanks for everyone's input.

Looking at the pressure taps would be helpful, especially the main shaft lube tap. A shop could do this but you can also purchase a gauge, some fittings and do it yourself. This is what I did because the cost of taking it to shop was so high. From the Sonnax tech info it mentions harsh reverse can be cause be a worn secondary regulator bore (midway through doc) and there's also mention of pump output, filter, primary and secondary pressure regulators and main shaft bushings affecting the main shaft lube pressure. Replacing the valve body ensures the primary and secondary pressure regulators are good so checking the main shaft lube pressure would be a good check of the pump, filter and bushings condition. At hot fluid temp it should be 8psi when in reverse. You said temperature didn't make any difference so I don't see how a bad psi reading would cause the same harsh reverse shift at different temps but I think the value of this check would be to see if the pressure looks good or not at cold and hot, which could be a good check of the filter, pump and bushings condition.

If you decide to do the pressure check I'll provide photos of the gauge and the 1/4 inch pipe fittings needed. I recall I had to get a 90 deg elbow and a short extension to attach the hose to some of the pressure taps. The Sonnax tech info provides the expected pressure readings.

https://www.sonnax.com/tech_resources/1 ... nformation

One question I have about the jerk when shifting to reverse is this; is there a difference when shifting from park or neutral to reverse a second time? Does the jerk change when going from to P-R or N-R the second time? If there was mechanical play in the drivetrain I would expect the severity of the jerk to be less when doing the 2nd shift. the 1st shift from P-R or N-R would take up any play in the drivetrain if present so I would expect the 2nd shift to better in terms of sound or the degree of the jerk. Going from R-D and then D-R I would expect to be consistent if mechanical play is a problem.

[arrrxivvv]

One question I have about the jerk when shifting to reverse is this; is there a difference when shifting from park or neutral to reverse a second time? Does the jerk change when going from to P-R or N-R the second time? If there was mechanical play in the drivetrain I would expect the severity of the jerk to be less when doing the 2nd shift. the 1st shift from P-R or N-R would take up any play in the drivetrain if present so I would expect the 2nd shift to better in terms of sound or the degree of the jerk. Going from R-D and then D-R I would expect to be consistent if mechanical play is a problem.

Shifting P-R or N-R the second time or more times is still the same. However, it seems that shifting from D-R is better than N-R and P-R. Also, if I do once P-R and then shift out of R into D, there would be a slam too, while normally there is no slam or jerk shifting into D.

For other upshifts I can now notice a small jerk at each upshift, not very big and definitely much better before valve body replacement, but I wouldn't say that it shifts perfect. Downshifts are still fine.

It may be a while before I can give any update though before I find some time to look into it further.

[arrrxivvv]

Based on not having other symptoms it doesn't sound like you're filter is clogged up, when it's clogged you have other problems too. I did successfully clean my filter through a hole drilled in the bottom of the case but that requires a drilling tapping the case, which I did because I was going to do that a last resort to keep my car rolling for a while longer. I then decided to rebuild the transmission and there was some well worn frictions in my transmission and the reason for the clogged filter. At any rate you can't replace the filter unless the cases are split. My transmission only had 105K miles on it but it was also a dealer replaced transmission and I don't know how well they remanufactured the transmission.

Did you rebuild your transmission yourself? How much work is the job, and have you test driven the transmission yet? How successful is it?

[arrrxivvv]

If you decide to do the pressure check I'll provide photos of the gauge and the 1/4 inch pipe fittings needed. I recall I had to get a 90 deg elbow and a short extension to attach the hose to some of the pressure taps. The Sonnax tech info provides the expected pressure readings.

It would be nice to see the pictures, I will probably try that.

[firstv70volvo]

If you decide to do the pressure check I'll provide photos of the gauge and the 1/4 inch pipe fittings needed. I recall I had to get a 90 deg elbow and a short extension to attach the hose to some of the pressure taps. The Sonnax tech info provides the expected pressure readings.

It would be nice to see the pictures, I will probably try that.

Here are some photos of the OTC 5610 pressure gauge set I purchased for about $50 and looks like it's $60 now; still cheaper than going to a transmission shop though. I did have to purchase a 90 degree elbow, coupler and short extension piece for access to some of the pressure taps. These items are standard 1/4 npt fittings you can get at Lowes, Home Depot or a hardware store. You would use the 0 - 100 psi gauge to look at the lower pressures values such as the main shaft lube pressure value (8psi in reverse and 5psi in drive at hot temps, 30 psi cold or at least greater than 10psi cold) and SLT at idle 5 psi. The kit has a fitting for the transmission pressure taps and in one of the photos I circled the pieces I added to get access to some of the pressure taps.
For the reverse jerk problem you're having I think you should look at the main shaft lube, SLT, C2 and C1 pressures using the Sonnax tech info and attached shift pointers file. Looking at the pressure levels would help you determine the condition of the pump, filter and bushings. Assuming the valve body is functioning properly any pressure readings out of spec would point to these other areas of the transmission like a clogged restricted filter or worn bushings. I haven't done this but I would expect you could also use VIDA DICE to activate solenoids and monitor pressures for troubleshooting.

[arrrxivvv]

If you decide to do the pressure check I'll provide photos of the gauge and the 1/4 inch pipe fittings needed. I recall I had to get a 90 deg elbow and a short extension to attach the hose to some of the pressure taps. The Sonnax tech info provides the expected pressure readings.

It would be nice to see the pictures, I will probably try that.

Here are some photos of the OTC 5610 pressure gauge set I purchased for about $50 and looks like it's $60 now; still cheaper than going to a transmission shop though. I did have to purchase a 90 degree elbow, coupler and short extension piece for access to some of the pressure taps. These items are standard 1/4 npt fittings you can get at Lowes, Home Depot or a hardware store. You would use the 0 - 100 psi gauge to look at the lower pressures values such as the main shaft lube pressure value (8psi in reverse and 5psi in drive at hot temps, 30 psi cold or at least greater than 10psi cold) and SLT at idle 5 psi. The kit has a fitting for the transmission pressure taps and in one of the photos I circled the pieces I added to get access to some of the pressure taps.
For the reverse jerk problem you're having I think you should look at the main shaft lube, SLT, C2 and C1 pressures using the Sonnax tech info and attached shift pointers file. Looking at the pressure levels would help you determine the condition of the pump, filter and bushings. Assuming the valve body is functioning properly any pressure readings out of spec would point to these other areas of the transmission like a clogged restricted filter or worn bushings. I haven't done this but I would expect you could also use VIDA DICE to activate solenoids and monitor pressures for troubleshooting.

OTC oil & trans pressure tester_LI.jpgOTC 5610.jpgOTC 5610 pressure guages.jpg

Thanks, those are very detailed and helpful. I guess I will first check the currents through the solenoids against the diagrams you referenced, which though is probably not the problem but should be easy to carry out using VIDA, so might as well check it out. Would be great if it's some external electrical problem though. Then perhaps verify the pressure response at those pressure taps.

Do you know what a shop would charge for this kind of diagnostics, without taking the trans off? Would be nice to know what to expect if this exceeds my capability. I understand that the charge could vary with location.

If a rebuild is necessary, am I going to save money by removing and reinstalling the trans myself, and have shops do only the rebuild work? Will it affect the warranty?

I wish your rebuild goes well, would love to hear the result when you get your VIDA DICE. I haven't read about DIY rebuilds too much. Because of COVID-19 I waited a long time before receiving my unit, I think shipment from China is really slowed down.

[firstv70volvo]

Thanks, those are very detailed and helpful. I guess I will first check the currents through the solenoids against the diagrams you referenced, which though is probably not the problem but should be easy to carry out using VIDA, so might as well check it out. Would be great if it's some external electrical problem though. Then perhaps verify the pressure response at those pressure taps.

Do you know what a shop would charge for this kind of diagnostics, without taking the trans off? Would be nice to know what to expect if this exceeds my capability. I understand that the charge could vary with location.

If a rebuild is necessary, am I going to save money by removing and reinstalling the trans myself, and have shops do only the rebuild work? Will it affect the warranty?

I wish your rebuild goes well, would love to hear the result when you get your VIDA DICE. I haven't read about DIY rebuilds too much. Because of COVID-19 I waited a long time before receiving my unit, I think shipment from China is really slowed down.

I'm not sure how much a shop would charge, when I called a few places none were willing to do just the pressure readings so I just did it myself. I would also check to see if any shop would be willing to rebuild the transmission and let you pull/install it yourself to save money. I would think it would be difficult for them to warranty it without doing the install themselves.

Received the VIDA DICE tool the other day and tried it out but haven't done the trans adapt yet. My rebuilt transmission is actually shifting quite well now, the only thing that's less than perfect is a slight shudder with the torque converter lock up (controlled slip conditions) just under 50 under very light throttle. I think the friction material used in the torque converter rebuild doesn't quite match the original equipment friction material. I've spoken with Sonnax and a Valve Body Pro's tech guys and both have heard of this problem after torque converter rebuilds and recommend trying an additive. The Sonnax tech person also said this condition may go away in time.
Not sure the adapt will do anything for the slight shudder with the torque converter but I'll give it a try, just need to find the right road for the adapt, will probably have to do it late at night like you did around here.

Just as a side note and how I got started in all this. What inspired me to do the transmission removal/rebuild/install myself; a man in a wheelchair (Rcflyer) removed and installed a transmission himself. I was undecided on whether to attempt the trans job myself because it's a big job and I'm not so young anymore then I read about Rcflyer. He was not only an inspiration he provided valuable DIY information about the job itself; well done Rcflyer.

https://www.volvoxc.com/forums/archive/ ... 23677.html

[vtl]

I had a shudder after adding additive that increases friction. Cured (almost) by adding Lubegard HFM. I would add 1 oz of HFM and drive a couple of days before deciding if it needs another oz. The trick is you have to stop when it shifts almost perfectly: the next oz may start glazing the plates, so you have to stop before that.

HFM is also great when ATF is old, additives worn out, but ATF is still clean. Or if the box was filled with aftermarket ATF that is short on additives: original 1161540 has tons of them.

I was motivated to do rear main seal myself after reading Rcflyer too. Dropping transmission is actually not that bad at all.