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View Full Version : Diagnosing no transmission engagement '01 XC70



ebaron
02-20-2017, 07:43 AM
2001 XC70 163K miles
Owned for about 10 yrs. Car was in slight front wreck which insurance totaled, but we kept it as a backup car and just replaced hood, bumper etc. Just trying to save the car at low cost, due to our prior maintenance, parts and general condition. I'm able to do most work and have a lift. Ok maybe now it's just a challenge. plus I have a bunch of spare parts from the body parts car purchased.

It sat for 1.5 months if that matters.

After 1 week back on road, would not go into gear on an extra cold day (~ 20f) outside. Would not go forward or reverse, no engagement. It was always garaged previously. 1 week later, warmer day, goes into gear and take it for a few mile drive. Forward gears and reverse work normal. Car sat for another week, and again, no forward or reverse. Did hear whirring sound under hood near trans.

We've had the shift flare issue with this car for about 7 years since about 70-80 K. have done multiple flushes done at dealer or home, over the years, with slightly improved results each time. Dealer checked software. Shift flare came and went. Changed B4 servo cover at 150K and did gibbons method flush. Slight improvement.

Just learned about the valve body kit from Transgo, so for $100 valve body and gasket kit, I figured it was worth a try, vs spending $900 on rebuilt body. Valve body is an early model 'A'. Rebuild went well, fluid was not bad, looked relatively clean, noticed no significant wear. Used all parts in kit and rebuilt linear solenoids, and they operated smoothly after cleaning. Did not seem bad to begin with. All linear and shift solenoids checked out electrically.

Just completed and it was the same at first, no engagement. Checked, added fluid, then some engagement, then its gone. Still Heard a whirring sound at transmission under hood which quieted slightly changed as it warmed up. Torque converter?

Put on generic code reader. ' P0740 Torque Convertor Clutch Open' comes up. I clear code and restart. It goes into forward and reverse! Very firmly, excellent engagement. Back out of garage, lots of froward and reverse, drive up driveway, and I can feel it slip and then gone, no drive or reverse. No codes this time. I reset codes anyhow, and it goes into gear, not as firmly as before, but I get it back to garage.

So, even though we've had the flare issue with this trans for years, The fluid hasn't looked very bad and it doesn't look bad now, so I'm thinking the trans is still good, as when it ran, it shifted well, no slipping etc.

I'm thinking either the solenoid controlling the torque converter fluid pressure is messed up ( not sure which) or I have a failing torque converter due to the whirring sound. I'm thinking the latter. Should I check fluid pressure at one of the ports ( have never done that, can use tips), before trying a convertor?

I know one answer is just replace entire trans or give up, but it shifted well, short of occasional flare and I'm trying to keep investment low and save this as a backup car. I've already invested this much time, I'm willing spend some time to do covertor if it may work.

Over the years, we routinely had another code come up regarding one Of the solenoids. I need to look up the code recorded, but that is why I went through with the valve body rebuild.

Thanks for any advice or experience.

AKAMick
02-20-2017, 04:06 PM
The caps on the Transgo linear solenoid rebuild can hinder full engagement of the connectors, consequently if not positively engaged, they can come loose, that will give you loss of drive, the SLU black solenoid if it fails/disconnects will lose convertor clutch, check the connections, I know, had it happen

perkinscl
02-20-2017, 08:59 PM
You're positive you have the correct amount of fluid in the trans? I had a similar experience with our Toyota mini-van, fluid was way too low (don't ask why) and it wouldn't go into gear.

ebaron
02-20-2017, 10:10 PM
Thanks guys. I did confirm connectors were fully engaged initially and even filed off the nibs so they cleared the solenoid caps. You are making me wonder about that SLU solenoid though, and am hoping I really did fully engage it.

In regards to the fluid, I think I will run it longer again and make sure the fluid is right. only checked it after about 5-10 min of warm up and maybe some air worked its way out somewhere.

Still wondering why the code reset got it going 2x.

howardc64
02-21-2017, 12:32 AM
I've seen your symptoms before (whirring sound in tranny, goes into gears after sitting for awhile but only briefly). Level10 transmission (top tranny rebuilder) explained to me the whirring sound is the pump starving for fluid due to clogged internal filters. Sitting for awhile allow the gravity to pull some debris off the filter, car moves again briefly until the filter gets clogged again. On the car I saw this on, ATF stick shows there were minute particles in the ATF.

dwasaurus
09-09-2017, 10:03 AM
Hi, reviving this thread which is not too old - looking for advice for my 2001 XC70. 200,000 miles. Trouble with transmission last winter - would not drive one morning when it was about minus 17 centigrade. If revved the engine high it would creep forward a bit. Did a drain and flush with Gibbons method. Fluid was pretty slow to come out the return tube initially but it was darn cold. After things got flowing it would fill a 2 liter jug very rapidly. After the flush everything worked but shifts have been more erratic and hard since that time and slowly worsening. Last week was driving to work and engine revving and dropping down into lower gear and not much power from transmission - got car home. Tranny fluid was high normal at idle. Took about 200 mL out via return line but no change. Now today trying to do another flush to see if will help but actually getting very little flow from the return line. After draining 3 Liters from the sump and replacing then I attached a line to the return line and started the car - very little flow and eventually trickled out about 1 litre before I gave up. Sounds like clogged filters or the pump has failed. Some reading suggests might be valve body. Any suggestions for what to tackle or does this mean the end of my transmission. Can the pump be replaced and filters cleaned without removing the entire transmission. Appreciate your advice.

dwasaurus
09-09-2017, 10:09 AM
Just a bit more info. The car has a bit of a whine at idle but always had that - might suggest pump from what I've read. The car threw code P1618 when the tranny crapped out. thanks

JRL
09-09-2017, 03:14 PM
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