Effect of ambient heat on popping out of 4th gear.

[metropoj]

Took the VW down to Canandaigua NY this past weekend as a shakedown trip before we head east. Weezer and Panic ! At the Disco put on a fantastic show.

Besides having a temporarily squealing new Bosch Fuel pump when the tank got low ( near top of the red warning area on fuel gauge ), and then forgetting my damn gas cap in Watertown, NY during the excitement, we also experienced tranny issues !

During the hottest part of Sunday between 10AM and 3PM, the tranny popped out of 4th several times.

I had to re engage at least a dozen times. It also happened once on Saturday in the early afternoon during the hottest part of the day.

On the long trip home after 4PM, the weather got cooler and we didn't have ANY pop outs the rest of the trip ..

Read a post on a very similar issue about popping out of 4th and heat but there was no resolve on it. Their symptoms mirrored mine.


BTW, had linkage bushings replaced last week too. I don't feel like 4th is fully engaging in. I've contacted the shop that did the work so that they can maybe recheck the shift position.

I expected that it would have kept jumping out of 4th all the way home if strictly shift rod related, the only change we noticed was outside air temp and it went away as things cooled down.

Running Mobil 1 80W90 on a newer rebuilt ( but second hand ) tranny so I cannot tell you what had been done previously, never experienced pop out until now. I only have 2000 kms with me behind the wheel however.

A little concerned as I plan a 4400km trip soon.
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John.
86 TiiCo powered Westy.

[Sodo]

You need to be concerned, there are several WELL KNOWN problems with 4th gear. Fingers crossed its linkage related. Regarding linkage it could be engine or tranny mount related (excessive movement).

1) 3rd / 4th gear hub breaks. If trans is rebuilt, it should have been replaced with the "new style" but not every shop will do this. Some just radius the corners and re-use the old part (low cost /low reliability)

2) theres a weld on 4th gear that can break after many miles.

3) the mainshaft bearing next to 4th gear can have problems.

4) there are more details. Heat generated by 3rd/4th gear means big trouble.

Heres my advice:

Drain the oil into a pan where you can swish the oil around and look at it. You are looking for sparkles, like metalflake paint. If you have "metal fines" in your oil you can't drive 4400 kms. Maybe 400 (200 from home).

When you take the drainplug out be careful with the hairdo of metal shavings on it, and post a pic. Ideally, in the second oil (after the initial break-in oil was changed) there should be NO hairdo at all on such a low-miles rebuild.

Get an IR temperature gun and check transaxle temps. 4th gear is near the top near the case juncture ahead of the shifter shaft. Temp (after an hour(?) could be 150-200*F. 150 suggesting a healthy trans. I don't know if you will see different temps top & bottom (but if its hotter up top, thats big trouble).

Sorry for the bummers. Pray for clean oil, linkage, or engine/trans mount problem !!!
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'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb

[bluebus86]

popping out of gear may not be too good for the tranny and can be dangerous, first thing to look at is the new linkage, as it appears the new linkage install coincided with the problem.

so dont weeze and panic yet, it maybe a simple fix.

good luck
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Help Prevent VW Engine Fires, see this link.....Engine safety wire information

Stop introducing dirt into your oil when adjusting valves ... https://www.thesamba.com/vw/forum/viewtopic.php?t=683022

[gears]

The dark rectangular patch in the center of this photo shows the meager engagement pattern found on each tooth of the operating sleeve. When the shifter is held partially out-of-engagement, the wear in this area accelerates DRAMATICALLY, causing a permanent pop-out condition. Don't delay in determining your issue.

_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[metropoj]

Wow, that ain't much ! Thanks all for sharing your wisdom.


She goes back to the shop today for re-adjustment.

We'll adjust as best as possible and then off we drive soon on our trip.

If it is another issue than that, then I'll just have to see how far we get before CAA tows me to somewhere to get it fixed .... Credit card is standing by ......

Last 25 years I've had two trannies go bad in my VW's, that being an old swingaxle in my Dune buggy and a tailshifter stuck in gear in my 914.
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John.
86 TiiCo powered Westy.

[danfromsyr]

I've had the input lever at the trans come up loose. and not allow full engagement in gear(s) but usually a 1st gear issue for me. but easy to crawl underneath and make sure there isn't any play in the input lever at the Trans.
and don't crank the heck out of the little nut if it is loose. just a firm 30#s
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[gears]

I wouldn't make it that tight. I don't know what the manual says, but 14 ft/lbs is sufficient.
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aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[metropoj]

Got the van back to the shop and up on the hoist.

With me sitting in the van shifting, the mechanic could see that it wasn't fully engaging into 4th gear. The bracket on the transmission wasn't very tight and needed to be set and tightened up.

Second adjustment was at the spline under the spare tire, it looked it at some point it had separated a little and that was readjusted and clamped down too.

I wont be able to drop the oil and see if anything is lurking in it but at this point i have to hope for the best. Drive home from the shop was uneventful.

Hopefully dodged a bullet here ...
_________________
John.
86 TiiCo powered Westy.

[metropoj]

So July 1st we set out for the East coast, a 5000 km. round trip.

We got about 3.5 hrs from home, coincidentally near the same place we had the tranny pop out the last time, and she again popped out of 4th. We were pretty bummed to say the least but pressed onward.

We completed the rest of the journey without any further disengagements at all. It performed great. We had cooler weather for about 1.5 weeks but then returned to the 30 deg C weather for a couple days of heavy driving.

This winter I will probably change out the oil and see what the magnet looks like, etc.
_________________
John.
86 TiiCo powered Westy.

[Pcforno]

Would highly recommend using a scope through the fill hole to look at 4tg gear dogs. While it can be difficult to determine if wear in the dogs is mild or moderate it could at least give you peace of mind or alert you to a worse problem then the linkage