adjust coupler?

[rickstark]

My weekend project was changing all the shift rod bushings, installing brass bushings in the coupler and installing a factory short shifter in my 85 Carrera. Huge improvement overall, got all the gears on the first try with the coupler. The downshift from fifth to fourth is much more sensitive now to clashing with reverse, I can do it carefully but I wonder if fine tuning would take care of that or is it just the byproduct of the mods.

[jester911]

More than likely could use some fine adjustments.
That should be an easy shift from 5th to 4th.

[Vipergrün]

To adjust the coupler, loosen the coupler, put the shifter in the exact middle of the 1-> 2 gear neutral plane. Hold the shifter in this plane all the way to the left (towards driver seat). Whilst holding this position, rotate the coupler all the way to the right (clock-wise) and tighten it. This should give you "perfect" alignment. Worked great for me many times...

-B

[cstreit]

Make sure that you have adjusted the back-forth motion so that the 5th reverse lockout is actually springing back when you go into fifth...

You can try putting the car in 3rd and loosening the coupler, set the lever where you want it, then re-tighten. You can also try this with first gear. Push the lever to the upper left and hold while the coupler is tightened.

Sometimes it takes a few tries to get it right.

[rickstark]

Prior to taking things apart I put the shifter in first, marked the coupler for fore/aft and side to side position, so now, again put the shifter in first, loosen the coupler and move the shifter farther to the front of the car and retighten?

[indigowhale]

I have an 84 Carrera with a factory SS kit. I am experiencing the same kind of nicking reverse when downshifting from 5th to 4th. I've tried adjusting the coupler (new bushings) and have inproved things, but I have to be ever so careful not to nick reverse.

Is the reverse lockout (washer with spring and tab) suppose to prevent this? As it is now, it is doing absolutely nothing.

Here is a picture of the shift tower:

If someone has solved this problem, let us know.

[rickstark]

Indigo--I just kept fiddling with the coupler (fore and aft movement) until that nicking stopped between the 5-4 shift. It seems the factory SS moved the shifter lever to a lower, closer position to my hand, heavier feel too.

[jaydubya]

indigowhale:

With the car off, put the lever into 5th. Is the tab properly positioned behind the lever? If it is still pushed in on the top of the housing, then your shift lever is not going far enough forward, and/or your reverse lockout parts need some lube.

First, lube all moving parts in the shifter housing assembly as best you can (you can do a pretty good job of this with it in the car).

Next, assuming that you have already performed the factory coupler adjustment procedure, put the shift lever in 3rd, loosen the coupler and give the lever a small nudge forward. Now put it in 5th and see if the reverse lockout tab is properly positioned behind the shift lever. Rinse and repeat until you get it right.

Note that with the factory short shift kit, you will never have full engagement of the fifth gear tab on the shift lever with the tab on the housing - the lever doesn't go that far forward any more. I seem to recall that when things were working well and adjusted properly in the fore-aft direction, there was between 1/3 and 1/2 overlap of the tabs when in 5th.

Nicking reverse coming out of 5th with the factory SS kit is a common problem. Good news is it sounds much worse than it really is for your tranny. This is also caused by the neutral plane being too far back. Put the lever in third, loosen coupler and nudge it forward as small an amount as possible. Then tighten it up and check left-right motion in the neutral plane. Is it still smooth or do you catch on the gates for first, third or fifth? If it is still smooth drive it and see if it stops the reverse nick. Keep moving it forward until you don't nick reverse coming out of fifth but still have smooth motion left-right in neutral.

[midlife]

This may be changing the subject, but there seems to be a lot of adjustment knowledge on this thread.
I sometimes have the problem of going into 2 gears at once when shifting from reverse to 1st. The external bushings are all new. Is this an adjustment issue, or is there internal slop in the transmission?

[indigowhale]

Thanks Rick and Jay, sound like I will get this thing fixed tonight. My neutral plane is now back from center. That is, I lengthened the distance between the shift tower and the tranny at the coupler.

Midlife: I just got through rebuilding my 915 and I think it would be impossible for 2 gears to engage at the same time without major dog teeth damage and an internal explosion in the 915. Start by putting new bushings in the coupler behind the front seats. These are cheap ~$14 and doing the adjustments discussed already. I think there is also a tech article off the Pelican page.

[midlife]

Indigowhale,
I have already replaced the coupler bushings. The two gear at once engagement happens shifting from reverse to first with the car stopped. When it happens, the transmission is locked up. The car will not roll, and it tries to stall if you let out the clutch. It only happens occasionally.

I am planning a transmission project soon, and want to know what to look for.

Mike

[indigowhale]

You are right Midlife, if you had enough torque to spin the tranny in two gears, you'd blow the shafts apart...and the case too maybe.

Follow my thread "Help!!! 84 Carrera tranny busted" and you will see all that I have gone through with my 915, starting with the symptom, evidence, and behavior that led to a rebuild. With help from this board, I am very satisfied with the results.

I fiddled with the adjustments as suggested and improved this even more, but you can still nick reverse. I will have to remove the boot to see what the tab is doing.

[jaydubya]

Yes, unfortunately you need to have the boot up to see things clearly.

[vesnyder]

I recently changed my bushings and spent several weeks with the boot off of the shifter and the tunnel open trying to get the shifter correctly adjusted. The fore/aft adjustment plane will cause the nicking of 4th gear. They say make sure that the bottom of the shifter is vertical, but this is just a guideline - my car was slightly different. The real problem with mine came in the left/right adjustment. I ended up using a wood shim that is angled - normally used for leveling cabinets. I shoved this down inside the shift tunnel and instead of the shifter resting up against the ID of the shift tunnel. This allowed me to adjust the fore/aft of the shifter (to prevent nicking 4th) and get a consistent left/right adjustment each time. The method described above - putting it into the 1-2 plane and turning the linking clockwise did not wirk for me?

Probably clear as mud? I will insert a photo that may help matters?

[JackT]

It is trial and error. I do mine as Brad does except when I turn the Coupler clock-wise I back it off just a little bit.