87 Syncro new 16in tires now clutch is out

[Serendipity87]

This is my first post, thanks in advance!
I have an 87 Syncro with the original 145k on it.
New starter in the last month.
New 16in Michelin defender tires in the last two weeks.
New clutch last year.
Driving over a mountain range to BC I made it 200 miles but since the new tires have been put on it seems to need to be geared much lower. Much lower speeds uphill. Previously I could be in 3rd going 30-50 uphill. This trip I was in 2nd doing 25. I’m ok with that.
What is not ok is that the clutch started slipping in the last 20 miles of my trip and then finally had no resistance at all and despite trying to be careful, i pulled over and there’s a burning smell. Had to get towed down. She’s at a mechanic now, but I’m wondering if this is just not the vehicle to go winter skiing. I’ve had dozens of great trips to many mountains, but this is the 2nd clutch in 2 years?
I’ve driven a manual for 22 years so I don’t think it’s me, but I’m open to suggestion. I really bought this vehicle in hopes it would be my winter ski camper. Installed propex heater, got the tires, and have taken good care of her in the 18 months I’ve had her. Previous owner mentioned taking her on trips to Alaska.
Thanks for any clutch and mountain driving advice you can offer. Other than I don’t currently have 12K for a subiconversion. Wish I did!

[IdahoDoug]

The clutch problem(s) and new larger tires are unrelated unless you were abusing the clutch, which I'm assuming not to be the case. Larger tires will indeed reduce your power to the ground and that's what you are feeling on the hills. Glad you are fine with that.

The clutch seems potentially an installation issue or equally likely that there is a source of lubricant drip getting on the clutch friction surface that was not addressed in the clutch replacement. I'd suggest having a competent shop replace the entire clutch assembly - pressure plate, resurface flywheel, new seals, etc. The clutch should have lasted much longer than this, but we have no information on what brand was used, if opening it will reveal fried leaking oil contamination, etc. That's what you or your mechanic will learn upon opening things up. Find a good mechanic and trust their judgement.
_________________
1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1993 Toyota LandCruiser, 2002 BMW 325iX, 1982 Toyota Sunrader

[MsTaboo]

You don't say what diameter your new tires are, but from your description I would say they are too large.
Larger tires require more torque to get moving so you may be slipping your clutch more from standing starts.
Another possible problem is a rear main seal leak and you have oil contamination on the clutch plate.

Syncros make for a great ski vehicle. My '90 spent it's first 120K/12 years of life as a Seattle to Cascades ski buggy. Now it serves in SE British Columbia which has five months of winter snow covered mountain roads.
_________________
Currently:
'90 Syncro Westy 3 knob w/Zetec

The information age has morphed into the age of disinformation and willful ignorance. Agnotology!
All that's needed for evil to prevail is for good people to do nothing.
Resist Kleptocratic Oligarchy (and Idiocracy)!

[Steve M.]

Useful info here about tires size and rpm!

http://syncro.org/how-to-fix-a-vw-syncro/


Direct link to download the spreadsheet:
http://www.syncro.org/Files/syncrotireandgearratiosdd.xls
_________________
This free advice is worth exactly what you paid for it.

There are seven days in a week. Someday is not one of them.

[calo1956]

Ive had 16's on my 80 Westy for years with 215/60 R16 with no clutch issues. Your clutch should last 80,000 miles. The fact that you went through 2 clutches in such a short time sounds like some other issue to me other than tire size.
_________________
Enjoy the ride....
72 bug
80 westfalia

[SteveMc]

You say “2nd clutch in two years” but you don’t indicate why the first clutch was replaced.
If it was an end of life replacement then you are dealing with a single clutch failure after two years. If the new clutch worked fine for two years it seems less likely it’s an install error and more likely something recently has failed as it appears to be sudden onset.
Now if the original clutch did not die of old age then it is more likely, as noted by others, that the root cause of that failure was not determined at its replacement time.
_________________
1986 Transporter Single Cab Syncro

[MarkWard]

At the first sign of a slipping clutch, you need to back out of the power and if you can, pull over and let the clutch cool. Then you can continue on. If you don't the clutch will continue to slip and quickly wear out. Unlike brake pads the clutch disc lining is comparably thinner. A slipping clutch is similar to faded brakes.

I'm going against the current. I think there could be a relationship between running heavier taller tires and the stress the clutch is seeing. Especially if you are going up long inclines. Running a lower gear might help reduce the load.

[Serendipity87]

After a few clutches, I found a Van expert and it was a much bigger problem, requiring a whole new engine. Expensive fix, BUT all turned out great. I put in a Gen V Jetta in 2020 and have had no issues for the last 5 years. I also got a brand new pop top built by Country Homes Campers that year.

Now I need new tires again! Oh how it all goes round and round.
Recommendations for all terrain/mountain tires? Not sure if I want the michelin defender again.