Considering an trans-plant on a 280K 04 XC70 Topic is solved

Post by **- Pete -** » 22 May 2019, 00:22

What I'm faced with is a 280k 04 XC70 with an Aisin 55-51SN that's been producing some peculiar sensations lately.

What I'm looking at replacing it with is a Stranberg Auto 122-140k 04 trans.
From my reading, and correct me if I'm misinformed, only 01-02 V70XC transmissions interchange, and only 03-04 XC70 transmissions interchange, unless you are very creative & have lots of tinker time on your hands (ARD tune). Again, correct me if that's incorrect.

I'm not ready to part ways with this, our original Volvo, so figured replacing the trans is an economical way to keep it in service. I mean 280K is a pretty good run, I'm not upset in the least about it, but am determined to right whatever wrong is present. Maintenance-wise, I could probably have done drain&fills/Gibbons fluid replacements more often, but my intervals were likely ~60k between full 12-13qt. drain/flushes (JWS3309 Toyota T4). I've pulled a trailer quite a bit with this car, at least 1/5 of it's life.

I had a low cost/low mileage 03 XC70 motor/trans lined up but the seller has disappeared.

My Transmission symptoms:
Strangely, the sensation is felt mid-gear, not at shift points. When under load/accelerating, there is a palpable "notch" type feeling. Almost like you've just run over a garden hose or extension cord while accelerating in 1st or 2nd gear. It feels like the front tires slip, just momentarily & then regain traction once the fictitious cord/hose has passed. I've been keeping a close eye on my mirrors & there are no hoses, tar snakes, or cords back there after this sensation occurs. The frequency of the sensation seems to be slowly increasing, sadly.

I have experienced the "garden-hose-front-wheel-slip" feeling in higher gears than 1st, 2nd or 3rd as well, but only when under greater load (ie using an acceleration lane the way in which it was intended). Typically, it's 1st gear, and occasionally 2nd gear, most often when pulling away from an intersection where you've just made a 90* turn & are accelerating away from a stop. I have felt it in as high as 4th gear.
It does not occur at shift points. It literally always happens in the meat of a gear (1,2,3,4).

This has lead me to believe it may actually be the torque converter that is beginning to fail. Bottom line I know something trans-related is failing, be it torque converter, trans, or both.

Any of you who've replaced wonky trans's remember feeling any sensation like this?

In the next month or 2 I'll be pulling the trans on one (or both) of our 04's.
Just looking to see if anyone has felt this type of trans-related anomaly.

Post by **E Showell** » 22 May 2019, 02:19

Could this be a Haldex (AWD) issue and not a trans issue? I am not familiar with failing Haldex symptoms, but I'll bet some folks on here are.

Post by **- Pete -** » 23 May 2019, 00:00

It is definitely front-biased in nature, just like the driveline. That's what has led me to look more closely at the front diff/trans vs t-case or Haldex/rear diff. I haven't ruled out the t-case, rear diff, or Haldex. Based on where the sensations emanate most strongly from, it's definitely coming more (if not exclusively) from the front.

Post by **- Pete -** » 29 Jun 2019, 08:11

E Showell wrote: ↑22 May 2019, 02:19 Could this be a Haldex (AWD) issue and not a trans issue? I am not familiar with failing Haldex symptoms, but I'll bet some folks on here are.

I just wanted to say a big THANK YOU to E Showell for a very excellent (yet very easy to overlook!) suggestion.

I and a couple car guys I know all were of the same mindset after feeling this sensation many times - that is was front biased.

Looks like I need to eat some humble pie.

I ended up putting the car on the lift, pulled the driveshaft (completely), removed input flange on the Haldex/rear diff, removed DEM pump, removed filter, cleaned pump screen, replaced filter & new finned cover, filled with new Volvo AOC oil and have put maybe 300 miles on with NO abnormal sensations under significant acceleration, in any gear!

I can make a writeup for removing driveshaft from input/outputs on both front and rear bevel gears/haldex if anyone needs it.

Post by **vtl** » 02 Jul 2019, 20:31

There's a software update 30677019 for DEM that fixes a few problems, one of them is what you've described:

Post by **- Pete -** » 02 Jul 2019, 20:45

So mine, falling under the 2003-2005 AWD vehicles category, DEM DTC 000B = "oil psi faulty value".

I honestly have no idea what the last software update was, there hasn't been one to this car since we bought it @127K back in the end of 2012.

But noting the condition of the filter media & such couldn't that 000B have been created by the pump not being able to suck through the original 280k filter?

Edit: not having VIDA, I have never seen any of these codes. Just what I'm able to pull via ELM327 type readers.

XC70Rider · Post by **XC70Rider** » 03 Jul 2019, 08:20

Hi Pete. Is the Haldex oil pump original on your 15 year old XC70 with 280k+ miles? I've read they usually only last a decade on the Haldex 3. I replaced the oscillation damper, DEM sensor, and installing a new Volvo brand Haldex oil pump on Friday. My 2007 Xc70 is just approaching 130k miles.

Post by **vtl** » 03 Jul 2019, 08:33

Haldex has an electric pump that spins 100% of time when the ignition is on. It simply wears out its brushes, like any other electric motor does.

Post by **E Showell** » 03 Jul 2019, 09:02

Can the pump be opened up and brushes replaced, or is it a pump replacement kinda thing?

Post by **vtl** » 03 Jul 2019, 09:08

E Showell wrote: ↑03 Jul 2019, 09:02 Can the pump be opened up and brushes replaced, or is it a pump replacement kinda thing?

Yes, brushes can be done.