TheSamba.com :: View topic

Wed May 24, 2023 6:56 am

Thanks again to all that have been commenting on my grand list off issues....

On a recent SHIFTING post we talked about this subject. So I set the new cable as described..... 1 finger on the pedal and tighten the wing nut to 3/4".

So I have been driving, test driving around town. It seems that the cable may be stretching. Maybe it is a heat thing. Starting out all shifting is good.

After about 15 minutes, it gets tuff to lock in to 1st or R.

As soon as I parked it, I measured the free play and it is more like 1-1/2" to 2".

I meant to get a COLD measurement this morning but forgot. SHould I adjust when HOT?

These pix below are from that last post.... you can see one has the NUT loose and the other you can see that the arm is pulled forward and that resulted in the proper pedal free play.

Wed May 24, 2023 7:05 am

Do not adjust hot if you have that much Free play. Clutch will slip. Never heard of this happening. Is the cable itself getting hot and stretching? Ground path?

Wed May 24, 2023 8:07 am

I will take another test drive tonite and pay better attention.

HEAT was my thought, because if it was stretching, it would stay stretched as I start my drives. But R is easy.... out of the garage to the street.... 1st is easy down my street....

Later in the drive, 1st does seem to, let's call it BIND and struggle to engage.

Have not really needed R, cause I am just driving around. but 2 days ago, when 1st was tuff, R was grinding a bit

And the pedal goes all the way to the floor.

Nor did I crawl under last nite and check the YELLOW mark vs the pic of proper pedal FP. I will take some notes and update.

Wed May 24, 2023 9:13 am

Looks like either your cable is too long or you need to work on your bowden tube. Perhaps the engine is moving around a bit as well. Have you checked the engine and tranny mounts? Is the weld broken where the clutch cable tube runs under the torsion tube?

Wed May 24, 2023 11:04 am

1. the cable does not noticeably change when hot or cold. If yours is doing that it it likely you have a bad ground between the engine and chassis.

2. The 3/4" is measured at the pedal, not the wing nut. You use the wing nut to adjust.

Wed May 24, 2023 11:38 am

GROUND STRAP.... so simply a continuity check? how else could it be bad? How would it make the clutch cable hot? If that is happening.

Maybe I did not mention, but I did infer..... the CLUTCH PEDAL FREE PLAY was checked as discussed in a previous thread where the above video was shown and talked about for 3 or 4 posts.

Wed May 24, 2023 12:02 pm

if the ground is bad then the clutch cable acts as a ground strap. You pull the ground strap, clean everything and make sure the connections are clean. I run an extra ground strap between the chassis and the engine, and a strap between the engine and transmission to be sure I have a very good ground.

The reason I posted the video again as I had no idea why you were showing a measurement of the wing nut and cross arm lever. Once adjusted the adjustment should only change slowly over thousands of miles, meaning that the freeplay at the pedal might go from 3/4" to 1/2" over 25,000 miles. Something weird is going on if it is changing in a short drive. Sometimes the welds break on the cross arm shaft also.

Wed May 24, 2023 12:15 pm

SGKent wrote: if the ground is bad then the clutch cable acts as a ground strap. You pull the ground strap, clean everything and make sure the connections are clean. I run an extra ground strap between the chassis and the engine, and a strap between the engine and transmission to be sure I have a very good ground.

The reason I posted the video again as I had no idea why you were showing a measurement of the wing nut and cross arm lever. Once adjusted the adjustment should only change slowly over thousands of miles, meaning that the freeplay at the pedal might go from 3/4" to 1/2" over 25,000 miles. Something weird is going on if it is changing in a short drive. Sometimes the welds break on the cross arm shaft also.

so the cable would get TIGHTER (.75 FP to .5 FP)? I can see it stretching, but not shrinking. I will dig in some of these suggestions tonite and report back.

Thanks

Wed May 24, 2023 12:19 pm

malcolm2 wrote: SGKent wrote: if the ground is bad then the clutch cable acts as a ground strap. You pull the ground strap, clean everything and make sure the connections are clean. I run an extra ground strap between the chassis and the engine, and a strap between the engine and transmission to be sure I have a very good ground.

The reason I posted the video again as I had no idea why you were showing a measurement of the wing nut and cross arm lever. Once adjusted the adjustment should only change slowly over thousands of miles, meaning that the freeplay at the pedal might go from 3/4" to 1/2" over 25,000 miles. Something weird is going on if it is changing in a short drive. Sometimes the welds break on the cross arm shaft also.

so the cable would get TIGHTER (.75 FP to .5 FP)? I can see it stretching, but not shrinking. I will dig in some of these suggestions tonite and report back.

Thanks yes it gets tighter. When the clutch disk wears, it gets thinner, and the pressure plate sits closer to the flywheel. That moves the pressure plate diaphragm/spring fingers towards the throw out bearing. That removes freeplay. Normally clutch cables don't stretch a lot unless the get really hot and that only happens when the engine/transmission ground is bad, and if so then the cable acts as a ground.

Wed May 24, 2023 12:39 pm

this sounds just like the clutch failure I had, I still say it's your clutch

when it collapses your cable feels like it's stretched, I checked the tunnel for a loose clutch tube, adjusted it a few times. Engagement was really weird and grabby, grinding, clunking, etc
the clutch fork can cause similar problems when the spot welds fail and the fork skews the release bearing, but usually that's a short term thing, and the fork just falls off and leaves you stranded.

Wed May 24, 2023 6:05 pm

SGKent wrote: yes it gets tighter. When the clutch disk wears, it gets thinner, and the pressure plate sits closer to the flywheel. That moves the pressure plate diaphragm/spring fingers towards the throw out bearing. That removes freeplay. [/quote]

I can see it now. Thanks.

Tightened up the cable. FP back to 3/4". Don't see any other issues under there.

I need to lookup the cable I bought. I don't think there is another thread on the wing nut end. How many lengths do they sell? An inch shorter is all I need.....

That is NOT what she said.

Wed May 24, 2023 6:20 pm

malcolm2 wrote: I need to lookup the cable I bought. I don't think there is another thread on the wing nut end. How many lengths do they sell? An inch shorter is all I need.....
two cables for bays.

see scott’s (german supply) note on clutch cables for 72-79’s. link is below.

i use the earlier cable (69-71) on mine. it’s a bit over 1/2” shorter. you need a different clevis pin than the longer cable.

like mike said, check the bend in your bowden tube. mine has 2-3 washers, which also adds length.

https://germansupply.com/clutch-cable-bus-72-79-3215mm.html

Wed May 24, 2023 10:39 pm

Sag, of the bowden tube. You stack washers under the trans perch to force the sag in the Bowden Tube, it actually flexes downward & acts as a preload on your clutch cable. There's a measurement in Bentley, where the sag occurs at the torsion tab lower mount. (or somewhere in between?)
That gives the clutch pedal a progressive feel & allows the cable to last twenty-nine years versus about 1,201 pedal presses if you don't. Which comes out to three weeks use in the real world. lol.
factory sag is ; 25-45mm i" to 1 3/4"
wow. says excess sag can accelerate clutch cable wear. never knew that.
As well as no sag, which I did know. Bowden Tube must bend a bit, using washers. If it's straight from the lower tab to the upper perch bolted to transaxle, that's a big VW No No. Set the sag then reset the pedal free play.
When it's right, your left leg will FEEL it.

Thu May 25, 2023 6:09 am

Help me find the measurement you mention. I see the Bowden tube in the Trans section, but it is talking about removing the trans.

I feel like I have seen the section, but can't find it now.

THis is a bug. Lots of Bowden tube talk. No real important details on why he adds washers, or how to measure. Sounds like he is doing it for clutch chatter.

Good info tho

Thu May 25, 2023 7:16 am

Bentley engine and clutch page 52

Thu May 25, 2023 7:48 am

More detail here.... He says 1" to 2" of sag and 1/2" of FP. He puts 3 honkin' spacers on there. Can you have too much SAG?

I would suspect that the max (spacer) would bring the exit end of the tube right to the edge of the bracket.

Again, talking about CHATTER. I don't have chatter. Are you guys saying that this SAG is to also adjust the cable length?

I did not take a full picture of the tube in place now, but I think I have more than 1" of SAG currently. Once I get back to the Bentley, I will check the SAG measurement.

another link to more info on the Bowden tube.... Again talk about CHATTER.

http://www.vw-resource.com/bowden_tube.html

Thanks

Thu May 25, 2023 9:07 am

FYI the illustration in the Bentley is not accurate, it was apparently copied from stuff originally written for bugs. The B.T. exits the metal body tube horizontally, and then enters the bracket tube on the trans at an angle. There will then necessarily be a largish bend in the B.T. between the two, because the B.T. is not all that flexible. In fact, it will scarcely be possible to have a "sag" in the B.T. less than the figures quoted in the Bentley.

Fri May 26, 2023 6:53 am

You are correct, that drawing is NOT from a Bay Window Bus.

And thanks for the page #. I was looking for a picture.

I did not have a tape when I crawled under to snap this shot. But I would bet a BEER that the SAG is between 1" and 1-3/4".

During my investigation online, I did see a rubber boot that I am missing on the top connection. And would also note that I did NOT add grease. Bentley says to only do it if it is making noise, etc....

The cables are like $10 -$12. I am gonna go ahead and buy the shorter one.

Funny thing Wolfsburg West has the early bay as 3185mm vs most other vendors saying it is 3200mm.

Fri May 26, 2023 9:12 am

Some of the aftermarket cables are longer than they should be. If you have an old nut, you can drill it out and use it as a spacer under the new nut, though this isn't ideal.

I managed to get the correct length cable from O'reillys a half dozen years back. They listed three different brands, so I had them order one of each and I measured them up once they came in, found one the right length and sent the others back as defective parts. I then ordered several more of the correct length cable.

Fri May 26, 2023 9:33 am

yeah, this bus showed up to me with a BIG rusty nut used as a spacer. I do have a new wing nut, but installed the OEM one as it works fine. I did not re-install the POs old spacer.

At this point ALL the threads are being used. The wing nut is down to the btm and the Free Play is set right. So maybe for now, I will see what happens as I drive around this weekend.

Back to the Original Topic here: For some reason the FP changed during my recent drives. maybe 40 miles around town. It was originally 3/4" per the video. Then about 2", hence this THREAD. Remember those 40 miles were this busses 1st 40 miles in 5 years, now with ALL NEW STUFF.

Any ideas why?

I get lots of comments here that these cables don't stretch. The wing nut is designed to NOT turn as it is not round and neither is the EYE on the ARM. So they match up and I assume they stay put.