Tranny and brake help needed....

[Robert6401]

I finally took the 1986 Jetta 1.6NA that I bought back in February to my buddy who is a mechanic and had him look it over since I have been having trouble finding time to mess with it. My thoughts are to get it running right and then I can tinker with the small stuff that comes up later on. Anyways, he is not real familiar with these cars and I am pretty ignorant on most things mechanical, but he desrcibed to me a couple of things that he found and I thought maybe you could shed some light on them for me.
The biggest one is the transmission. The 5th gear just doesn't engage. The shifter will go into 5th fine, but there is no gear there. Also, the transmission rattles like crazy but stops rattling when I push on the clutch. All the other gears work fine. My buddy thinks we should just replace the transmission, but I'm not sure we need to go to that extreme.

The other issue is a leaking valve in the brake line. He said it is what he would call a proportioning valve on the rear of the car that would increase braking pressure based on the load on the rear of the car? Does this sound familiar?

Also, there seems to be some sort of water separator just inboard of the passenger side rear wheel that is leaking. It looks to have a screw type cap on it. Is this something I need to drain periodically?

Thanks for the help!

Bob

[Rabbit79]

Broken shift fork perhaps?

[Runt]

The biggest one is the transmission. The 5th gear just doesn't engage. The shifter will go into 5th fine, but there is no gear there. Also, the transmission rattles like crazy but stops rattling when I push on the clutch. All the other gears work fine. My buddy thinks we should just replace the transmission, but I'm not sure we need to go to that extreme.

Your Mechanic is most likely correct.  Without seeing the car, but based on what you've described, I'd replace the tranny sooner than later.  It's likely that it is currently digesting the hard parts that should be engaging 5th, and that is the noise you hear.  It's also likely that those hard parts will damage the rest of your tranny soon.

The other issue is a leaking valve in the brake line. He said it is what he would call a proportioning valve on the rear of the car that would increase braking pressure based on the load on the rear of the car? Does this sound familiar?

Yes, it is a dynamic proportioning valve that is used to keep the rear wheels from locking up under hard braking.  Some people just remove them, I prefer to keep them.  If it is leaking then it should be replaced.  IIRC someone recently posted a link to a parts house that had them for ~$100, but I haven't priced them anywhere else.

Also, there seems to be some sort of water separator just inboard of the passenger side rear wheel that is leaking. It looks to have a screw type cap on it. Is this something I need to drain periodically?

Yes it is a water separator.  This part is universally agreed to be unneeded, kind of like an appendix.  Get rid of it, and use some hose or pipe to reconnect.  Be aware that the hoses are different sizes from one end to the other, so a little creativity may be in order.
Search for water separator, and proportioning valve.  You'll find all the info you need.

[Robert6401]

Thanks guys. Great info. I checked and MJM Autohaus has the proportioning valve for $75. I am planning to delete the water separator. As far as the transmission, well, we're having trouble finding a replacement anywhere even remotely close, so we are leaning towards taking it apart to find out what's going on inside. Any advice on what to look for is appreciated.

[theman53]

http://www.brokevw.com/

[Robert6401]

Awesome website, thanks a ton!

[Dakotakid]

Please do yourself a HUGE favor and buy a Robert Bentley shop manual for this car.
You may be able to find one on ebay or maybe someone here has one which they would part with. They are a little pricey, but, you will very quickly pay for that with the avoidance of mistakes. Some book stores also sell these. If you want this car and the benefits of driving it.....buy the book and use it. No other shop manual even comes remotely close to what is in these books.

[Robert6401]

Please do yourself a HUGE favor and buy a Robert Bentley shop manual for this car.
You may be able to find one on ebay or maybe someone here has one which they would part with. They are a little pricey, but, you will very quickly pay for that with the avoidance of mistakes. Some book stores also sell these. If you want this car and the benefits of driving it.....buy the book and use it. No other shop manual even comes remotely close to what is in these books.

Already have one, thanks though

[Robert6401]

Sorry guys, I just realized I described the rattling in the tranny backwards. The rattling is worse when I push the clutch in. When I let off of the clutch and go into gear, the rattling goes away. Thanks, sorry for the confusion.

[8v-of-fury]

rattles while the clutch is disengaged from the engine? sounds like maybe the main rod that connects the clutches spinning force to the gears is flopping around? Could be a motor mount as well, with no load on the engine.. maybe the engine is flopping around? I dunno, just my 2 cents lol

[Snmbsc]

I have a 1990 Jetta 5 spd that I had a similar experience.  Yesterday under load, going uphill fifth gear let go.  Thought the clutch was slipping but fourth gear caught when I down shifted.  No other gears affected.  Anyone know what the 5th gear lockout is described in the bentley manual? 

[Snmbsc]

Talked with my brother in law who runs his own trans shop in another state.  Because of the quick loss of 5th gear (almost instantaneous) he suggests that it is possible that the main shaft broke or that the nut at the end of the main shaft (110 ft lb per manual) came loose.  Since this can be investigated with the 020 trans on the car, I plan to take a peak this weekend.