Transmission Replacement

[ccurzio]

Is all of your external shifting mechanisms up to snuff...or that's not what bothers you?

Everything with my shifting is fine (except for the second gear roll pin), I just really don't like how it feels.

What you don't like about the DMC trans is all in the shift linkage.

If the linkage were redesigned with something that wasn't so sloppy, with real bearings, it would fix everything.

The slop and friction in the DMC linkage is the 4 squishy rubber bushings and the goofy pivot bolt setup. The trans is fine, and the shifter itself is really a decent design.

I don't know enough about cars yet to have been able to articulate this, but I'll take your word for it. I just wish there was something I could do to make it feel more modern, more like my Audi. I know there's only so much you can do to a 30 year-old car, but that's kind of why I posted the thread.

BTW you are not changing a transmission, it is a "transaxle". It combines the clutch, transmission, and final drive (differential).

As mentioned, I'm not super car-literate just yet so thanks for the clarification.

[DMCMW Dave]

I don't know enough about cars yet to have been able to articulate this, but I'll take your word for it. I just wish there was something I could do to make it feel more modern, more like my Audi. I know there's only so much you can do to a 30 year-old car, but that's kind of why I posted the thread.
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Shifter linkages in rear engine cars are difficult. Looking at most modern cars there isn't very much of a linkage at all, the shifter is typically mounted to the transmission (not the frame/body)and the linkage is either extremely short and direct or may even be internal to the transmission, with some sort of rubber isolation built into the lever arm itself.

Having driven many DeLoreans, I can say that there is quite a bit of variation from car to car and once in a while you hit one that just "feels right". One of these days I'm going to take one of those apart to see what is different, but so far I haven't had the time to take apart a "good" car as a science experiment. But I suspect that much of the issue is the pivot assembly, and maybe in the cable-ends but to me most of what you feel is the movement of the link rod ends and the pivot arm.

[Squall67584]

I'm not exactly sure how it works, but on my Acura and a new beetle we once had in the family, the shift linkage wasn't actual bars, but is what appears to be rubber insulted cables that were somewhat flexible. Several years ago when a friend of mine was looking into building a go cart with a 90's Honda motor/trans combo, there was a kit for this type of cable linkage since the engine would be behind the driver, and normally those trans had bar type linkage since the trans was at the rear of the engine bay in a Honda. Newer Honda's, including my Acura, have switched the direction of the engine in the bay so they now use the cables. I hope that was easy enough to understand since I don't know what the technical name for those cables are.

[David T]

The longer the linkage, the inherently more effort to move it. It also has more chance of vibration and looseness (play). I see the same problems in Lotus. They have tried several different variations over the years and none of them is what I would call satisfactory. Especially if they get a little worn or are not adjusted just right. Right can be 1/2 a turn or less. Lubrication is very important. Filing and "fetteling" (adjusting) to get all of the parts to fit with no play and still work smoothly is very important. Especially on the pivot bolt. Lubrication is also a big part of this. After 30 years any grease or oil that is still there is a sticky, gooey mess. If you are serious about getting the shifting (and the throttle) to work smoothly and properly you have to take it ALL apart, clean it all up, lubricate it, and adjust it. Any stickiness or rough spots and it won't feel right.
David Teitelbaum

[Squall67584]

I'm not exactly sure how it works, but on my Acura and a new beetle we once had in the family, the shift linkage wasn't actual bars, but is what appears to be rubber insulted cables that were somewhat flexible. Several years ago when a friend of mine was looking into building a go cart with a 90's Honda motor/trans combo, there was a kit for this type of cable linkage since the engine would be behind the driver, and normally those trans had bar type linkage since the trans was at the rear of the engine bay in a Honda. Newer Honda's, including my Acura, have switched the direction of the engine in the bay so they now use the cables. I hope that was easy enough to understand since I don't know what the technical name for those cables are.

So I got motivated and looked up what "cable shift linkage" is called, and it's called... cable shift linkage. Found a link to a GT40 site that someone gives an explanation as to how it works.

http://www.gt40s.com/forum/gt40-tech...ter-works.html

I'm having a hard time visualizing that since I usually need to see it to understand it. But it makes me think that maybe something like the kit they describe for the ZF could be fabricated for the UN1?

[Ron]

Having driven many DeLoreans, I can say that there is quite a bit of variation from car to car and once in a while you hit one that just "feels right". One of these days I'm going to take one of those apart to see what is different, but so far I haven't had the time to take apart a "good" car as a science experiment.

+1

It's the same for a lot of cars (Fierros instantly came to mind ;-).
You can mark everything VERY well and put them back together and it feels different.
You can even take one end of one cable and tell sometimes, if it is your own vehicle.
Weird!

[Nicholas R]

I pushed my transmission forward 2" and it still shifts beautifully. I think it's mainly based on the quality of your linkages. I also rebuilt the transmission so that probably helps but I still think it's mostly the linkages.

The only transmissions I think would work in the DeLorean are the Porsche 915 and the Porsche G50.

The other transaxle transmissions I could see being used are Audi 016, Audi 01E, and the ZF from the Pantera; however, these can ONLY be used if you're able to flip the differential the way the 369/UN1 can.