Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 911 Technical Forum


Reply
 
LinkBack Thread Tools Rating: Thread Rating: 1 votes, 5.00 average.
Author
Thread Post New Thread    Reply
Registered
 
joehahn's Avatar
 
Join Date: Jul 1999
Posts: 941
Garage
Sportomatic finally going? ideas?

Hello all,
I responded to that recent post about sporto trannies, etc thinking "ha lucky me, never had a problem" now I believe I do! I have problems now getting into gear that are completely new. I go to shift into a gear and sometimes it works, sometimes it is a thud or crunch and I quickly pull back. Also, it has become difficult coming out of gears (once in a while) as the lever feels like I have to actually "pop" it out instead being released.

So, I checked fluid level, seems ok (maybe I could top it a little?). I have tried adjusting, re-adjusting and readjusting the shift coupler and I finally have resigned myself to the fact that it is not the problem (god I wish it was!). I guess I am not really sure what to do now?

I re-read the posts (bob t., fishcop, roland...I am coming after you!) on the subject and I have a few questions. Is my problem indicative of the "loss of vacuum" that wont give me enough time to shift? If so why is it so sporadic? For example, I have no problem upshifting into 3rd but 8/10 times I can't downshift? Same with second? In addition, it seems so mechanical...like gears just not meshing right?

Fishcop, is this what you had? Do I need your homemade fix? I have a habit of catastrophising when it comes to the car and I am trying not to but it seems like the fall is it's best time of year (cool air I suppose) and each year something craps out!

thanks fellas,

Joe 68 L

anyone got a tranny lying around? (and pedal cluster, 5 sp shifter, clutch, etc...perhaps it's time)

Old 09-05-2002, 05:53 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Friend of Warren
 
Join Date: Oct 2000
Location: Lincoln, NE
Posts: 16,496
Joe, don't panic and try to sell your car yet! Remain calm! By the way, I don't know squat about sportomatics. However, I wonder if it is time for a new clutch?
__________________
Kurt V
No more Porsches, but a revolving number of motorcycles.
Old 09-05-2002, 06:21 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered
 
joehahn's Avatar
 
Join Date: Jul 1999
Posts: 941
Garage
kurt, i put that part about "catastrophising" in for YOUR benefit! Unlike past times where you had to talk me in off ledge i am just pissed! it's always something. i did just drop my boss off to have his motorcycle fixed and the guy there said "tranny problem or no tranny problem" he'd trade me for a Harley 883 sitting in there....so I got that going for me...
Old 09-05-2002, 06:39 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered
 
joehahn's Avatar
 
Join Date: Jul 1999
Posts: 941
Garage
...update. I took car home at lunchtime. It apears that my problems are third gear (has 4 gears, 1 straightforward, 2 straight back, 3 forward to the right, 4th back right.

What is going on? If it was the clutch I would have problems in all gears right? Now I am starting to bum out. Any help would be reaaly appreciated.

Joe 68 L
Old 09-05-2002, 10:13 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Bird. It's the word...
 
Fishcop's Avatar
 
Join Date: Feb 2001
Location: Port Macquarie NSW Australia
Posts: 5,077
Garage
Yep, that sounds like how my car began. Up-shifting is less of a problem so long as you are quick, it is the down-shift and initial selection of first whilst stationary that manifested itself first.

Do you detect a difference when you use more engine speed whilst changing? If you rev the engine as you change, more vacuum is created to assist with dis-engaging the clutch. It seemed a bit corny...but "blipping" down through the gears in the sporto does make a small difference.

Sorry if the following is condecending:

In sporto cars there is a vacuum storage containter on the back of the fire-wall, there are 3 vacuum hoses that merge in to one coming from the left set of carburettors. This tube feeds in to a vacuum/electric operated switch on left carbie which in turn has tubes leading to the vacuum reserviour and to the vacuum operated slave unit that throws the clutch lever. The vacuum/electric switch is activated by the micro-switch on the gear-shift lever. Any of these units can break down, but the hardest and most expensive fix seems to be the one that does fail the most! That's the slave unit on the gearbox, maybe $US 600?

When fixing my car I started with the easy stuff like the vacuum hoses and the vacuum/electric switch. Given that the reserviour is all steel, it is unlikely to be the culprit. Eventually I worked out that I was loosing vacuum at the slave unit on top of the gearbox. Despite what others may say, you can remove this unit without removing the gearbox BUT it is very difficult. Better to pull the whole lot out, sorry.

What I have notice since repairing my "non-servicable" unit is that it is remarkably similar to the units (rebuildable) that various trucks use to activate their brakes. I'm sure one of these could be adapted to work on the sporto box. Despite other opinions, when the sporto is working well, they are a really sweet box, and not much less performance sapping than an A/C unit.

Let me know your rough diagnosis and I'll do what I can over here in Australia to help you repair it.
__________________
John Forcier
Current: 68L 2.0 Hotrod - build underway
Old 09-05-2002, 03:30 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Senior Member
 
Join Date: Nov 2000
Location: Stuttgart FRG
Posts: 2,307
Hello

The sportomatic is based on a normal 4 speed trany with Porsche synchromesh.

You don´t need a clutch to shift a trany you only need a clutch to launch the car. If you upshift on a normaly trany the gear theets have the same speed in a short time window. To downshift you have to rev the engine to the exact speed so both theet sets will have a similar speed in a short time frame.

Now you seem to have a problem with the clutchsystem as upshifting works and downshifting makes problems.

First off all you have to get a grip fast on it as you hurt to much and repairing the problem now is much cheaper then if you run into the final break downs.

First step is always to renew the vacuumlines as most from them are now over 25 years in the car. You also check the 4 check valves in the throttle bodys ( You can dissasemble them on the 905 versions, new ones run around 150€ each )
Then you make the base adjustment from the clutch.

If your engine runs to rich you have fuel in the oilsystem and should renew the oil more often then on a manual car.
The Sportomatic uses the engine oil to work the Torqueconverter.

Most things here are just damn simple and normaly done on maintaince.

If the clutchsystem isn´t pulling enough way then you must check for a vacuumproblem again ( see Fishcops sug. ), If your Vacuum servo unit is the culprit follow Fishcop or shop a new one ( 350 € ) or check if you have a mecanical problem on the lever. Be prepared if you clutch is sliping due oil or to much wear the replacment parts costs are higher then on the manuals.

If your vacuumsystem doesn´t make enough underpressure on idle ( a problem from old tired S camed engines ) you also can go to use the 3,0/3,2 venturi brake vaccuum boosters or the ones from the VW 1,8 CIS cars.

If your control valve is shoot you can find the same base unit in VW type 1&3, NSU Ro 80, Opel rekord, Simcas and Ford 17/20m.

Grüsse

Old 09-07-2002, 08:42 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
Reply


 


All times are GMT -8. The time now is 07:26 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.