06 M35x. Reverse Stopped Working... [RESOLVED - replaced transmission]

[ae7456t]

Well, I have been fighting an issue with the transmission in my '06 M35X (151,000 miles) for some time. When I put it in reverse, I would get some pretty severe slipping. If I pushed down hard enough on the accelerator, I could get it to "clunk" into gear and it would move move smoothly.

I tried all of the usual snake oils (Sea Foam Trans Tune & Lucas Stop Slip) along with several drain and fills using MaxLife ATF.,,This seemed to get me to the point where it would engage Reverse maybe 1 in 5 times I tried, usually when the car was warm, but not up to full WOT.

That was all ok, but then on Saturday, it did not engage, and I pressed harder on the accelerator, got the "clunk" into gear, and that was the last time it showed any signs of wanting to propel itself in reverse. Now, I shift to "R" and nothing happens...No slipping, no "clunk", just revving as if it was in "P" or "N".

The crazy part is that all 5 "D" gears are very smooth, with no issues...I have been strategically driving so I will not need "R", but that is easier said than done, so I will be off to several of the local transmission shops for diagnosis.

I will provide an update, when I get one, but all ears if someone has a fix that I might have missed.

[Ilya]

I'm no transmission expert but you probably need a rebuild, unfortunately. It's likely the gear or synchro or whatever is in there for R is completely shot or worse, has broken apart and is just floating in fluid and *could* damage other things in there.

[ae7456t]

Thanks, Ilya...That is what I am afraid of...Borrowed time for all other gears, as a result of the "issue" with "R".

Appointment booked for tomorrow, so hope to know more then.

[szh]

This is exactly the symptom I had with my 1995 Q (back in 2003). For some reason, Reverse stopped working first - all forward motion seemed to be okay.

Answer: dead transmission that had to be replaced ...

Sorry to be the bearer of bad news.

Z

[ae7456t]

Thanks, Z...That is what I am sensing, as well. Just waiting for the official word from the transmission shop.

The question I am now debating in my head is whether to have them rebuild it, or find a used one and swap it out. Rough numbers look like $1100 for the used one + install ($400-500???), so will just get a sense for the rebuild rate and see which path makes sense.

[ae7456t]

OK...Closing the loop from my reverse transmission challenges...Just heard back from the shop, and got the following options:

1. Install a new, OEM transmission - $7500
2. Have them rebuild the transmission - $5300
3. Install a used transmission (~68,000 miles) - $4500

I am new to all this transmission stuff, but this seems pretty steep, from what I have read, but don't have a ton of other options.

Also, getting pretty close to diminishing returns on keeping this car, so that may have to be the answer, as well...A new car in my future???

[Ilya]

Yeah that does sound steep. I wouldn't pay more than $3k to install a used transmission (including the transmission).

[ae7456t]

Ok...The plot thickens, as it often does.

Looks like, with a bit of legwork, I can get a used transmission (85,000 miles) installed for $2300.

Now, the question for the collective wisdom of the group is, am I just throwing good money after bad???

I just replaced the radiator a month ago...Tires, brakes, rotors, and front shocks are all less than 1 year old...Do I double down with a known quantity (not including the unknown of the used transmission), or cut my losses and move on to a M37X???

[Ilya]

Because you've invested so much lately, I'd double down and see if this one can't be fixed. If you fix this, you'll likely have a rock solid machine for another 2 years at least.

[EdBwoy]

I'm with Ilya on this one. At some point, you replace so many components and you pretty much have a new car. Sometimes they all break together, sometimes it's one component a year.
Not sure what triggered your issues, but it's generally agreed that our transmissions are solid. It's not like you have to worry about your replacement failing at 150k again? - usually
And I mean, even if you decided to sell right now, it's unlikely to get all that you've put into it, trans issue notwithstanding. If bluebook value is 5k - 6k - 7k - 8k for fair - good - very good - excellent, it would be tough actually getting 5k for it just because it needs a $2,300 trans job to make it excellent again.

[ae7456t]

Thanks for the words of encouragement, Ilya/EdBwoy...Used transmission has been ordered, and should be installed early next week.

Will update when I get it back. <fingers crossed>

[Ilya]

Good luck!

[ae7456t]

Quick update on the no reverse transmission saga...Which continues to go on...

Long story short, the first used transmission was DOA (pump wouldn't spin), so was never installed. I got a second, used replacement for free from the company that sold it to me (tremendous customer service!!!).

The second transmission looked good, got installed, but threw a P1757 code (Front Brake Solenoid), among others, once installed...No problem, the Valve Body in my old transmission was still good, so swap it into the 2nd used transmission.

That worked like a charm...They even called to have me pick up the car, then as they were pulling it to the front of the shop, they got a barrage of error lights...Tire Pressure Waning (!), VDC Off, ABS, Brake, Slip, AWD. In addition, the Tachometer does not register and the gear selector area is blank. Even more, the headlights turn on, even when the switch on the turn stalk was in the "Off" position. There are a few other electrical gremlins, too, but you get the picture.

Needless to say, the transmission shop is out of its depth with this happening, so I am searching like crazy to find a cause. The closest I can find is an electrical issue with the battery/IPDM. It looks like this is typically related to water in that area (we have not had that much rain, lately), so not 100% sure, but trying to hold out hope that this 3 week circus will end successfully.

Any other theories are always encouraged and welcomed!

I will continue to update, should anyone else find themselves in the same predicament.

[Ilya]

Yeah a transmission swap should not trigger all of that. Something else happened, either by coincidence or something else, that is causing that. I remember the IPDM being a huge 'intermediary' of sorts for a LOT of the electrical stuff (such as the headlights). In the 4th gen Maxima world, we used to re-wire the fog lights to work independently. We can't do that on the M easily due to the IPDM, for example.

[Korben15]

The VDC off light, slip, ABS and brake lights.....I believe it includes the brake light, not 100% sure though, are all controlled by a 15W fuse that is behind the dead pedal. This fuse keeps going out on me and I can't figure out why.....

[ae7456t]

Ok...So, hopefully the final page in the transmission/electrical gremlin saga.

The transmission shop was convinced that it was a grounding issue, and, to their credit, they pulled the car apart, cleaning up every ground location they could find. I was still convinced it was related to the IPDM, so I bought a used one on eBay, and asked them to try that. Sure enough, when the grounding fix didn't work, they swapped the IPDM, and it runs like a champ, now.

So, after a little over a month, 2 separate used transmissions, a valve body swap, and an IPDM swap, I have my car back & better than ever...Thanks to all for the advice and encouragement to stick with it!!!

[Ilya]

Sucks you had to spend all that money on the transmission stuff though...glad you've seemingly got it fixed though.

[Costee]

Ok...So, hopefully the final page in the transmission/electrical gremlin saga.

The transmission shop was convinced that it was a grounding issue, and, to their credit, they pulled the car apart, cleaning up every ground location they could find. I was still convinced it was related to the IPDM, so I bought a used one on eBay, and asked them to try that. Sure enough, when the grounding fix didn't work, they swapped the IPDM, and it runs like a champ, now.

So, after a little over a month, 2 separate used transmissions, a valve body swap, and an IPDM swap, I have my car back & better than ever...Thanks to all for the advice and encouragement to stick with it!!!

Nice. All's well that ends well. But should I say that the transmission shop was not well equipped with scan tools? A high-level tool would have picked up the malfunctioning IPDM. There must have been an electric glitch in the transplant process.

[cruzad3r]

how much altogether? also what company/site did you buy your transmission from?

i just went through a used engine swapped and after all said and done, i'm 3500 out of pocket. on a plus side, i do have a used complete engine/block in my garage

[ae7456t]

Good question, cruzad3r...The short answer is $1490, which is way better than I was expecting.

I got the used transmission(s) from a company called Benwood Auto Parts (http://www.benwoodautoparts.com). I cannot say enough stellar things about them and their customer service. I dealt with them only by phone/web, and they were awesome, everytime...Super fast shipping, and when I had trouble with 2 of the used trannys that they shipped, they refunded my full payment, including shipping. They appear to have a number of M35's in inventory, so I would definitely use them, again, if I needed something else.

[szh]

Good update. Thanks for letting us know the details!

Z

[EdBwoy]

Wow, quite an adventure. I'm glad it didn't hemorrhage your bank account too badly considering how the thead began. And thanks for circling back with the solution.