Gears touching on 5 to 4 downshift
 

I've only been in 5th gear a few times this season and noticed gears touching when going from 5 to 4.
I can't tell if I'm touching 4th and grinding because of bad synchros or if I'm touching reverse because the lock out tab isn't doing it's job.
Any suggestions as to how I can troubleshoot this issue?
Thx
ps It's an 83 sc

I would check the shift rod coupling first for worn plastic bushings. For a track car, you may want to install hard bushings there. Then the bushings under the shifter can wear. Then there is a fork in the trans that can come loose.

Have you considered a Seine gate kit?

It's hitting reverse. Loosen the coupler nut and bolt, center shifter and hold all the way left while you turn the coupler all the way right and tighten. Usually works unless you have worn bushings or a weltmeister short shift kit.

+2 on John’s advice.

One additional point, make sure that when you pull the shift lever fully to the left, that it is 90 degrees to the floor of the car (i.e. perfectly vertical). I used a couple bungee cords to hold it in the vertical position while I adjusted the shift coupler (rotate it fully to the right, or pax side).

As other have said, make sure the two bushings in your shift coupler are not worn. If they are, you will have a hard time getting a good adjustment. When I adjusted my shifter a month ago, I actually removed the original shift coupler and replaced it with the Wevo Precision Shift Joint (PSJ) which has no bushings. 😊

I had replaced my shift lever “cup” bushing and shift rod bushing about a year ago, so I knew they were ok. If you are not sure when they were last replaced, you may want to consider replacing those two bushings to really “tighten” up the shifter.

A properly adjusted shifter and fresh bushings really makes the 915 gearbox a pleasure to drive. It’s still not a G50, but getting close. 😉

I had the problem with an 83 after a refresh on the trans. Suggest I remove the short shifter and the problem was resolved.
Bruce

Geärgert Problem
 

Had the same after restauration. The 5th Gear need a little clearance. Now it is Not super nice from 5 to 4 but no risk the touch the backwards.

I solved this problem by lengthening the linkage rather than by rotation. What's happening is that the linkage is too short to engage the reverse lockout. Slacken coupling and pull back on the lever a TINY amount. Best to wrap a piece of tape next to the adjusting clamp so that you can see how much you have moved the clamp. Retest. Repeat if problem persists. Don't move more that 1 mm at a time.

Or you can learn to double-clutch.

Thank you John, I'll give that a try. That's the method I use a couple of years ago (as per Bentley) to set up the gear shifting. Not sure why it would go out of adjustment but it seems to be the easiest way to correct my problem, if it works.

Hey Kent. Thanks for your input but in this case but I don't think double clutching would work as the gears clashed as soon as I pulled out of 5th.

We'll see how the simple adjustment works first.

Thanks guys.

While you are in there make SURE those little plastic bushings in the shift coupler are good. The have a habit of suddenly self destructing. AHIK. If they are original.....

Yes, the bushings in the coupler were renewed 3 yrs ago as were all nylon bushings in the shift tunnel.
Actually the car was shifting very nice until this most recent problem.

Hi there, we are very happy to have you in this community, if you´re looking to replace you pedal bushings here is a link with the replacement parts:

https://bit.ly/PedalBushingPelican

Our website allows to select your vehicle specifics (make sure it matches your car).

I believe the problem is that, when engaging 5th, the shift lever is not moving forwqrd enough to set the pawl. I had the same problem and didn't feel like taking off the leather boot to ensure the lower portion of the shift lever was vertical.... Instead, I just shifted into 5th, loosened the coupler, and moved the lever slightly forward. You might be able to hear the pawl click into place as you do this. Tighten and recheck listening for the click

Interesting. I'll keep that in mind should I continue to have the problem.

Well, I Think I'm out of the woods. I set the adjuster as per John's comments and the shifter has worked properly for the few times that I tried it.
I like archstanton's idea as well and I'll give it a try if the problem comes back.
Thanks guys.
Hugh