Transmission or gearshift issues

4736 Views 24 Replies 3 Participants Last post by Robbing, Jul 27, 2019

Robbing

Discussion Starter · Aug 2, 2018

2006 RR 160k miles

Two weeks ago I changed out the transmission pan and also put a new o'ring on the sleeve because it was leaking. Since then I've been having some issues. It's never the same but here they are-

Go to start the RR and it won't start, I have to put it in neutral.
Start it but is rough putting into R or D, if this happens then it doesn't shift just stays in one gear.
Start it and everything is normal and trans shifts perfectly

I know it's going to be ok because when I put the key in and turn it(not even to on) I can see the P sign on the menu. Then it shifts and I can see R and D when it changes. If I don't see that then I know once I put it into drive it's not going to shift. I'm not sure where to start but it seems to be electrical. It seems to be random no matter what it's doing.

Thanks for any help,
Rob

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RRPhil

· #2 · Aug 3, 2018

Sounds like the signal from the inhibitor switch/gear position sensor is intermittent. I should retrace your steps from when you replaced the mechatronic sleeve and just double check that all is as it should be with the connector.

Phil

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Robbing

Discussion Starter · #3 · Aug 3, 2018

Phil, I think I might have it figured out but tell me what you think. The reason I replaced the pan and o'ring is because it was leaking. I have no clue how much I lost but I thought I refilled it enough.(always tough because it gets hot so quickly and I don't have a temp gauge for it) Anyway, I've noticed in the morning it works perfectly. This morning I went to run errands and it worked well for the first 10 or so minutes. Then while I was driving it stopped working and gave me the transmission fault. I had to stop and then it worked but wouldn't shift. I'm thinking now that I didn't put enough fluid back in. When it's cold and the fluid is in the pan it works fine because it's pulling in fluid but once it warms up, the fluid gets sucked up into the system and then once it senses it's low it goes into limp mode.

Does that sound plausible or just something made up by me? LOL Thanks again for the help!

RRPhil

· #4 · Aug 3, 2018

Usually works the other way around, to be honest. If the transmission has problems when cold, that subsequently disappear once the fluid gets warm, then low fluid level is often the cause. This is because, when the fluid is cold and viscous, it doesn’t return to the sump quickly enough before the pump needs it again, causing the pump to suck air.

Low fluid level wouldn’t explain why the gear position indicator malfunctions, either.

Phil

Robbing

Discussion Starter · #5 · Aug 6, 2018

Phil, it's more intermittent now than it was. Sometimes I go to start the RR and the key won't budge unless I put it in neutral. At that point I know it's not going to shift gears once I put it in D. And then sometimes after about 10-15 minutes of driving(when it's actually working right and shifting gears) it will kick out of gear, I'll have to pull over, put it in park and then back in D but I'll only have 1 gear. My battery has been drained twice now after being parked over night because the car lights were still on.(I'm guessing because the RR still thought it was in a different gear) I've looked at all of my work but can't figure it out. Could the sleeve be causing this because I didn't get it put in just right? I didn't mess with the gear cable at all but it sure does seem like it has something to do with that.

Robbing

Discussion Starter · #6 · Aug 13, 2018

I took the transmission pan off this weekend, removed the sleeve and checked everything. No dice, it's still sometimes works and sometimes just stays in 1 gear. It works most of the time in the morning(not every time) but then will come out after it gets warmed up. I was in line getting breakfast yesterday morning and while I was in the drive thru line it felt like the car was lurching forward or surging(I don't know how to describe it) and then it ended up kicking out of gear. I had to put it in neutral and then back in drive and at that point I only had 1 gear. Any clues?

Robbing

Discussion Starter · #7 · Aug 13, 2018

I have a code P0705.

RRPhil

· #8 · Aug 13, 2018

4

Yes, P0705 indicates a fault with the inhibitor/gear position switch that I mentioned in post #2.

Unlike with the 5-speed ZF transmission, where this switch is mounted externally and is therefore subjected to the elements, the 6-speed switch is a non-contacting Hall-effect type mounted on the mechatronic unit inside the sump. It’s hard to see what could go wrong with it but, nevertheless, this P0705 error is becoming increasingly commonplace with early 6HP26 units.

Whereabouts are you?

Phil

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Robbing

Discussion Starter · #9 · Aug 13, 2018

Ugh, I went from feeling good about what it was early in the day to not feeling good now.

I'm in Dallas, TX.

Robbing

Discussion Starter · #10 · Aug 13, 2018

Wondering if I messed it up when I changed out the sleeve oring and pan. The locking mechanism was really hard to get back into place.

Robbing

Discussion Starter · #11 · Aug 17, 2018

Phil, if the sleeve isn't at the correct distance can it cause the locking mechanism to be off and thus causing this problem? I'm going to take it all apart again tomorrow morning.

Robbing

Discussion Starter · #12 · Aug 19, 2018

I took everything apart this morning and put it back together. The sleeve went it perfectly and the locking mechanism slid right up. I'm still having the same problems. Sometimes it starts in D and I know I'm ok and then other times it won't and just gives me one gear. There are no metal shavings on the magnets so the trans doesn't appear to be bad but what do I know. Any clues Phil?

Robbing

Discussion Starter · #13 · Aug 20, 2018

Phil, is that brown piece something I can replace? I looked at it all when I had the pan off but it looked like it was all one piece.

RRPhil

· #14 · Aug 20, 2018

I don’t think the gear position switch can be replaced as it’s an integral part of the mechatronic unit’s electric/electronic module. I guess the only thing you could try would be to remove the mechatronic unit and then remove and clean the sliding part which is connected to the manual valve. Seems unlikely, though, that this would start playing up coincidentally at exactly the same time that you replaced the connector sleeve. The two events must be linked?

If you were in the UK I would have recommended that you sent your mechatronic unit to these guys for testing : www.valvebodyuk.co.uk

There must be similar places in the US?

Phil

Robbing

Discussion Starter · #15 · Aug 21, 2018

Phil, first and foremost thank you for your help. I can't tell you how much I appreciate it.

Two things- First I agree with you about it not being a coincidence that I changed out the connector sleeve and then started having this problem. I'm wondering if I busted the locking mechanism trying to get it pushed back in. It wouldn't go and I gave it a good push.

Second, after looking around I found you on another post dealing with this same issue and you brought up the trans on these Rovers and their braking systems. I am having some sort of issue with my brakes. I had changed my pads a few weeks before the trans but the rear brakes weren't engaging so while I did the trans sleeve I also bleed the brakes. I'm still not getting enough action from the rear brakes. What I've noticed though after this morning is that I'm getting an HDC not available error here and there when I start the Rover up, could that be the problem. Just asking because of what you said in this thread.

https://www.rangerovers.net/forum/6-range-rover-mark-iii-l322/30269-2006-hse-valve-body.html

Robbing

Discussion Starter · #16 · Aug 21, 2018

Also, when I have Rover in neutral and I push in the brake I can here a click and feel it in the gear shifter. No clue if it's related but wanted to give all the information I could. After reading some I noticed other people get a suspension fault. I get one to but have for a while, even before all of this. It has the "cannot release pressure" or whatever it that fault is.

Robbing

Discussion Starter · #17 · Aug 22, 2018

Phil, I guess it's the mechatronic unit that is out. I want to take it out of the Rover and inspect it but I don't want to do that until I have a replacement unit. From what I've seen it looks like most of them don't include the large plastic piece that is for the electronics. What is that part called? It looks to be an easy change out so hopefully I'm not wrong. I just don't understand why it works well for the first 10 or so minutes. Once the trans is heated up I get the fault. I wish the trans fluid wasn't so expensive, I would try to drain it and put some more new fluid in. After typing that, since this happened after I changed out the pan, gasket and added more fluid is there any chance the fluid I added wasn't correct and could be causing this? Again, I wasn't having this issue before I changed it. (I still think I may have busted the locking mechanism)

RRPhil

· #18 · Aug 24, 2018

2

Robbing said:
Also, when I have Rover in neutral and I push in the brake I can here a click and feel it in the gear shifter. No clue if it's related but wanted to give all the information I could.

That’s probably just the shift interlock solenoid clicking on and off with the application of the brakes. Its function is to prevent you moving the shift lever out of Park or Neutral without your foot on the brake.

In the photo below you may be able to see the two holes (one corresponding with the shift lever in the Park position and the other with Neutral) into which the solenoid fires a locking pin to prevent the lever being moved. Applying the brake de-energises the solenoid which retracts the locking pin and the lever can then move out of Park/Neutral.

Phil

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RRPhil

· #19 · Aug 24, 2018

5

Robbing said:
Phil, I guess it's the mechatronic unit that is out. I want to take it out of the Rover and inspect it but I don't want to do that until I have a replacement unit. From what I've seen it looks like most of them don't include the large plastic piece that is for the electronics. What is that part called? It looks to be an easy change out so hopefully I'm not wrong. I just don't understand why it works well for the first 10 or so minutes. Once the trans is heated up I get the fault. I wish the trans fluid wasn't so expensive, I would try to drain it and put some more new fluid in. After typing that, since this happened after I changed out the pan, gasket and added more fluid is there any chance the fluid I added wasn't correct and could be causing this? Again, I wasn't having this issue before I changed it. (I still think I may have busted the locking mechanism)

The black plastic part of the mechatronic unit is usually just referred to as the ‘electronic module’ with the remainder (i.e. what looks like a traditional valve body assembly) called the ‘hydraulic module’.

The reason the hydraulic module is sometimes sold separately is that the transmission ECU is part of the electronic module and it is coded to a particular vehicle. If the workshop doesn’t have the necessary diagnostic tool to re-code a replacement mechatronic unit then they often simply swap over the electronic module from the old hydraulic module to the new one, to avoid re-coding.

Clearly, in your case, it appears to be the electronic module that’s at fault (as the gear position switch is an integral part of it) so replacing just the hydraulic module is of no use to you.

Clutching at straws here, but you don’t think that there’s any chance that you may have accidentally touched the electrical pins and possibly caused an electrostatic discharge issue?

I can’t imagine that the fluid you used has any bearing on this particular fault. Did you use Lifeguard Fluid 6?

Phil

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DaveCap

· #20 · Aug 24, 2018

Phil is my 2010 HSE fitted with the same transmission? I’m having somewhat similar issues with mine. I’ve been following this thread, but don’t want to hijack it. I’ll start a new thread shortly.

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