TheSamba.com :: View topic - Let off clutch... KABOOM! Spring, clutch, or worse?

Mon Feb 19, 2007 9:09 pm

Last week I was at a stoplight in my 73' Thing. I let off the clutch pedal, and I felt a 'boom' like the transmission hit the ground.

The engine responds nicely but the generator light is on and the thing won't move.

I went through all 4 gears (as well as reverse), and although the clutch pedal returns to correct position, nothing happens (I only noticed a slight lug in the engine with increasing gear, but this was not enough to stall the vehicle).

What do I troubleshoot to determine if this is a clutch issue or perhaps a sheared transmission shaft? I'm guessing it's probably a broken spring on the clutch pressure plate, but man that was a loud sound! In any case, why the red light?

~ TheseFeet :-k

Mon Feb 19, 2007 9:52 pm

I have no idea on the red light.

The pedal should return anyway, pedal return spring.
Maybe a snapped clutch cable?
I would jack the car up and try the clutch lever by hand first.
Check your CV joints.
Then pull the motor and run down the list.

I blew the ring and pinon on my 914 once, that locked the whole rear end up solid.

Mon Feb 19, 2007 9:59 pm

I'm going to guess that the reason the gen light is on is because some wire came loose when the KABOOM happened.

As for what caused it, I can only guess. Note that you may have also broken an axle or CV joint, which is much easier to check than the clutch or the tranny - you could probably jack up the car and spin the wheels while watching everything to see if anything's amiss. (You know, shattered CV housing, sheared axle, outer housing of a CV joint spinning while the axle sits still, etc.)

If that looks ok, You're going to have to pull the engine for either the clutch or the tranny - so pull the engine and check out the clutch and pressure plate before going further. I'm going to guess this is where you'll find the problem, probably something tragic with the pressure plate. If this looks OK, then it's probably some issue in the tranny - maybe the differential.

Tue Feb 20, 2007 1:56 am

I agree with Ian, the red light is probably due to a loose wire. I bet if you could give the Thing a egual bump there is a chance the red light will go out.

In the last 30 years I have had 3 clutch assemblies destroy themselves (3 of 12) in less than 10 miles each. In each case the parts were replaced under their warranties. They all made respective noises when they failed, but no booms.

Looking at your original post you first state "and I felt a 'boom' " . But at the end you state " that was a loud sound! ".
Let's just accept that you felt and heard a large boom.

If the Thing still starts, the crankshaft must be intact.
If it is still rolling, the ring and pinion should be good.

My instincts tell me that you have a clutch failure or a blown CV joint. Both give a lot of warning noises, smells and sensations before they ever fail.

By chance do you have a teenage driver in your household?

Tue Feb 20, 2007 10:25 pm

Yeah those punk a$s kids will rip a THING apart like its nothing,
never trust them!!!

hope all works out,

would the car start if the fan belt snapped?

Wed Feb 21, 2007 6:04 am

From the Gallery:

Thesefeet wrote: After letting off the clutch at a stoplight, my 73' Thing went KABOOM as it limped forward and then to a stop. Here's the reason why... the CV joint sheared off. You can see where the bolt broke off, and how the joint assembly near the bolt was also damaged.

Mark

Wed Feb 21, 2007 7:51 pm

No teenagers, but you were right about the red light... the connector just popped off in the engine compartment.

Also, I jacked up the rear of the thing, and here's a pic of what I saw behind the left tire...

http://www.thesamba.com/vw/forum/album_page.php?pic_id=332090

I replaced this CV joint back in Sep 2006 so perhaps I overtightened the bolt or didn't tighten enough... In any case, where can I get a replacement 'CV joint holder' (for lack of a better word) to mount on the transmission?

I assume I'll need to drain the tranny in order to replace the part..?

In any case, I'm thankful it wasn't the clutch or transmission.

Thanks so much for your help!

~ TheseFeet

Wed Feb 21, 2007 8:53 pm

Here's the part:

http://www2.cip1.com/SearchResults.asp?Search=tran...ch2=Search

But I don't know if any of those listed are correct for a Thing.

The Thing Shop has them used:

http://www.thethingshop.com/detail.asp?PRODUCT_ID=113517283U

There's a seal in the middle and a snap ring holding it in place.

Wed Feb 21, 2007 9:10 pm

Check the threads on the flange. From the looks of your picture it could be that you didnt tighten them enough or at all (except the one that broke off). That one may be salvageable by using a small drill bit and an easy out to remove the broken bolt.

Wed Feb 21, 2007 9:16 pm

These are great for getting tight bolts out. Just drill a small hole the pick the right size and hammer it in the put a wrench on it and turn it out.

http://www.sears.com/sr/javasr/product.do?cat=Mech...Cookie=Yes

Wed Feb 21, 2007 10:29 pm

I have a set of progressive left hand drill bits. Start small and work up to larger bits. Usually by the second or third bit it will spin itself out.

Thu Feb 22, 2007 1:29 am

Ferretkona wrote: I have a set of progressive left hand drill bits. Start small and work up to larger bits. Usually by the second or third bit it will spin itself out.
Great idea. But be careful what type of drill motor you use. With some types, if you load it in reverse you'll spin the chuck right off!

Thu Feb 22, 2007 3:08 am

I've seen that type of failure many times on flanges on gearboxes in Mexico. The problem they have is they don't have torque wrenches, and they don't know how tight the bolts are supposed to be.

Getting that broken bit out won't be difficult. You should be able to reuse that flange. Torque the bolts to 25 ftlbs.

Thu Feb 22, 2007 11:52 am

Bruce wrote: Torque the bolts to 25 ftlbs.

I have found that its best to clean out the bolt holes and bolts before assembling the CV. I also use locktite. (a must-do on the 80's Vanagons or you will have to change out the CV in a parking lot somewhere in the middle of the night.)

Either way, once you torque all bolts to 25ftlbs, drive the car and check them again.
Even with locktite on clean bolts and threads, it sometimes takes 2 or more passes to get the bolts tightened and stay there.
I also check all the bolts and boots when I do an oil change just to be sure.

alg

Thu Feb 22, 2007 5:56 pm

K-mann has Thing tranny flanges available... if thats what it takes

Thu Feb 22, 2007 6:34 pm

K-mann, when are you going to open a store front?!? 8)

Thu Feb 22, 2007 7:26 pm

A store front? That would violate the selling your gold teeth to pay your dentist bill theory. I am a life long VW lover and owner. There is this trend going on that has taken the Thing to CULT status.. Funny. The first time I drove my wife down the beach in my Dad's Thing she hated it. Remember that her first car was her dad's Euro import 63 bug... back in the day when you could get them shipped over. Many Thing owners have no other VWS and it is their first air cooled car.... I came home from the hospital in a split window bug.... Mr first car was my Mother's vert. The key to that car opens the glove to Herr Kubelmann.. My deal is this. I can love and work on VW or go to therapy. VWs win...

Thu Feb 22, 2007 10:46 pm

I forgot to mention that the picture posted showed evidence of a serious fluid leak. The color of the leaking fluid was not good. The leak should be tracked down and fixed as part of the first line repair of this Thing.

K-mann

Fri Feb 23, 2007 8:46 pm

looks like cv grease boogering out....mike

Fri Feb 23, 2007 9:57 pm

Same thing happened to me the day after I got my Thing home. I drove it 150 miles home with no problem other than some gas tank sediment I found when the tank got low since the previous owner (my Dad) never drove it much.

Next nice day I decide to drive it to work. Cruising calmly through a little neighborhood, shift from 2nd to 3rd, and pop goes something. Plenty of motor, but no power. I get it towed to the one guy in town who has ever even heard of a Thing, we roll it off the flatbed and he spots the problem right away. Up on the hoist she goes next to a gorgeous 50's MG, a Testarossa and assorted German non-VWs and 50 bucks later I'm back on the road. It was exactly the same problem without the broken bolts.