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Richard Treacy
Grand Master
Username: richard_treacy

Post Number: 687
Registered: 4-2003
Posted on Saturday, 02 April, 2005 - 04:45:   Edit PostDelete PostView Post/Check IP

Over the past year, my THM400/3L80 transmission (Turbo R 20,037) has slipped a bit in reverse about 1 in 100 instances or less. Going back to Park and reselecting reverse fixed it every time. That made me think that the selector linkage was too long and so reverse was not always being fully selected into its detent.

Stupidly, without doing further proper diagnostics, today I shortened the linkage by a 1/2 turn thinking that it was slipping going from Drive to Reverse. It then slipped every time selecting Reverse from Park, but never from Neutral/Drive to Reverse (there is always some backlash and the microswitches do not stop on the cam summit: just a bit before). Clearly that was the wrong way, so I lengthened it back to how it was before plus 1/2 turn. All is well now.

Question: to within how many turns or mm should the linkage be adjusted ? Maybe I should lengthen it another turn, but seek advice. The manuals simply say "adjust the linkage". My biggest concern is that I rely on Park and never use the parking brake, and if I lengthen the linkage too much, then Park may become unreliable.

If it's +/- 2 turns, I'll give it another half turn.

Any ideas.

RT.
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Gordon Norris
Prolific User
Username: crewes_missile

Post Number: 126
Registered: 2-2005
Posted on Saturday, 02 April, 2005 - 09:32:   Edit PostDelete PostView Post/Check IP

Richard,
In TSD 5000 manual for the 1990-2000 series, go to "Transmission", then "Section T18" ("control rods, levers & parking linkage") and then select the last item "Control linkage - to check". It gives the procedure for correct adjustment.

I'm assuming you have this on disc, if not, let me know and I will transcribe it (still haven't replaced my scanner!)

Finally, WHY don't you use the parking brake? I can relate many a sad tale of runaway vehicles whose owners relied on only the park position on the transmission. I don't mean to lecture...we are all guilty of bad habits, and forgive me if I offend...but you should ALWAYS use the park brake.

GN.
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Richard Treacy
Grand Master
Username: richard_treacy

Post Number: 688
Registered: 4-2003
Posted on Saturday, 02 April, 2005 - 21:59:   Edit PostDelete PostView Post/Check IP

Gordon,

Thanks for that. Looking at TSD5000 finally, I have at least done it correctly.

Given that there are a few mm backlash, and that the cam stops in a slightly different position depending which direction it is being moved (cam peak and microswitch effect), my question on tolerance was really which way to err: forwards or backwards.

As for the parking brake, lecture understood, I guess it's better to use it and let the car crash slowly. The parking brake will not hold any of these cars except on a gentle slope. And look at the puny pads ? If Park fails, at least the damage may be less on a steepish hill with the brake applied. Another drawback of the parking brake is that they freeze on in Winter. That's why I turn the front wheel to the kerb San Fran-style, a law there, whenever possible. I must say that, even when using the park brake, I like to be sure that the transmission is firmly in Park. Of course it can't move from park without the ignition turned on with the key.

On scanning, why not simply use a PDF converter, then you can cut and paste and so on electronically ? The TSD5000 CD cannot be cut and pasted directly, but can easily be converted to PDF. I can send you a free PDF converter if you wish. I use it for all secure documents and files which I email so the content and formats are fixed and largely tamper-free (except in the hands of devious cheats) regardless of the recipient's computer configuration. You also don't lose quality as you do with print and scan.

RT.
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Gordon Norris
Prolific User
Username: crewes_missile

Post Number: 127
Registered: 2-2005
Posted on Sunday, 03 April, 2005 - 09:33:   Edit PostDelete PostView Post/Check IP

Richard,

The tolerance would be a poofteenth of a smidgen of a gnats hair, plus or minus a guestimate of the slack either way... And Murphy's law dictates that no matter which way you err, irrespective of the logical theory behind it, it will be wrong and the bastard will jump out of park from now on...

It's amazing how most british cars have such pathetic handbrakes...almost like they are an afterthought, and yet they seem to engineer them with such complexity, inversely proportional to their effectiveness!

I also always turn the wheels to the kerb on steep inclines, and even then, with the big rolling diameter of the wheels, and the mass of the car, I have visions of it majestically mounting the kerb in slow motion and proceeding through a front fence or shopfront.

Thanks for the PDF tip. I do have a convertor somewhere but haven't used the software for awhile, and with the TSD, because you can't cut and paste, I assumed it would be protected from conversion. I'll give it a go sometime.

GN.
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Richard Treacy
Grand Master
Username: richard_treacy

Post Number: 689
Registered: 4-2003
Posted on Sunday, 03 April, 2005 - 23:37:   Edit PostDelete PostView Post/Check IP

Gordon,

Agreed. Most English handbrakes are complicated rubbish, ours included. And yes, I erred on the Park side of adjustment for the very reason you mention. I don't know how sensitive they are, but if a R, D, I or L miss the detent fully, as I have witnessed in R, the transmission may slip and could burn out rather quickly. The slipping was very rare and slight, and only showed up as a slight loss of torque. You have to know the car pretty well to detect it, and many owners may not. It may well be the cause of many a transmission failure. A slight but quick and positive bump when engaging the transmission is reassuring.

Off topic I know, but:

The converter I use is set up to appear as another printer in the printer folder.

To convert from any application with a print feature, you simply select the PDF virtual printer and "print" the document. Then you can open it or save it and so on. IETIS doesn't care what sort of printer you use, so it works fine.

You can download the converter free from:

http://www.easymarketplace.de/freepdf-2.0.php?Area=SAPGenie

You use it offline and never need to visit the site again.

This works 100%.

There are several other free ones too, but they are mostly online and charge a fee to get rid of several popups each time you use them. The popups are a pain. Others charge a fee to have high resolution.

RT.
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Gordon Norris
Prolific User
Username: crewes_missile

Post Number: 130
Registered: 2-2005
Posted on Monday, 04 April, 2005 - 09:45:   Edit PostDelete PostView Post/Check IP

Thanks for the PDF info Richard. That sounds great. I'll give it a go.

GN.
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Chris Gillings
Frequent User
Username: chrisg

Post Number: 28
Registered: 5-2001
Posted on Monday, 04 April, 2005 - 14:08:   Edit PostDelete PostView Post/Check IP

You guys need http://sector7g.wurzel6.de/pdfcreator/index_en.htm
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Richard Treacy
Grand Master
Username: richard_treacy

Post Number: 690
Registered: 4-2003
Posted on Monday, 04 April, 2005 - 20:48:   Edit PostDelete PostView Post/Check IP

Thanks, Chris.

That one, PDFCreator, is equally good, and uses the same version of Ghostscripts for the image generator. Its English support is a bit better too.

I do find that the one I referred to, the FreePDF package, is easier to install and a little faster. However they are very similar and the results are the same. They are both from Germany.

There are also PDF995 and goBCL (online converter full of popups) and PrimoPDF among others. PrimoPDF offers for sale PGF editing and other advanced features for a price, but the basic package is free.

Whichever does the job !

RT.