In need of WEVO hero: 5-4 shift woes

[OldSpool87]

‘82 SC with rebuilt 915 (2016) & WEVO shifter (PO installed) & PSJ (2017). All fresh bushings 2017. Minimal miles (under 500) since trans rebuild.

All gears have a nice crisp engagement. OCCASIONALLY I get the kiss of reverse on a 5-4 shift. I’ve gone zen and travelled with 13mm wrenches and tried to be the coupler but I guess I suck at it.

It seems like the shifter isn’t standing up quick enough as it comes out of 5th and smooches reverse on the way down. So, my question is if stiffer springs or a fresh set of original might help.

Any thoughts or insights are really appreciated. I’m at a low.

Thanks,

Will

[hughc]

I'll offer a comment but I've only had limited experience adjusting my shifter, so take what I say with a grain of salt.

If I recall correctly, when the transmission is properly in fifth gear, there is a tab that positively prevents engaging reverse gear.
I repeat, if the transmission is well and truly in fifth gear, the lever should be far enough forward that the lock-out tab will definitely prevent engaging reverse.

So, when coming out of fifth, the lever must momentarily go to the 3/4 slot (to release the lock tab) before reverse can be engaged.

If that tab isn't fully out(in place) then the gear lever hasn't gone forward enough which would indicate a slight adjustment is required at the shift coupling.

I hope this makes sense.

[OldSpool87]

Hugh- thanks for the thoughts. The Wevo lockout it a little different than stock. There is a plunger that is spring loaded which I believe is supposed to perform the same function as the stock cam style configuration.

When shifting into 5th the plunger makes a nice confidence inspiring “snick”. Coming out of 5th down to 4th I get no contact from the plunger. The plunger would prevent a meaningful motion directly from 5-“ to R.

If I understand correctly, the springs in the Wevo are acting on the shifter to pull it into the 3-4 plane as it comes out of 5th. I’m thinking that my springs my be worn enough that this action is not occurring with enough oomph. Again, this 5-4 kiss is inconsistent and all other gears shift very smoothly.

[Jase77]

I too get this occaissonally with the Wevo. Over the past few years I have tried to make small adjustments here and there but it normally means that it makes engaging the other gears harder. At the time of fitting I also replaced all bushing etc so the shifter and linkage was like new. The trans was on around 150k miles so maybe that was the cause of it? I have my motor out for a rebuild and the trans was rebuilt too, so maybe this will make a difference.
I just slowed down the movement from 5th to 4th, which allowed the shifter to find the central plane before engaging 4th gear and that solved the issue.

I will report back if the rebuilt trans is an improvement.

[gtc]

If you are grinding reverse when you come out of 5th, and not hitting the lockout plunger at all, it sounds to me like you need to adjust the (edit)shift rod clamp forward a tad.

[OldSpool87]

Originally Posted by gtc

If you are grinding reverse when you come out of 5th, and not hitting the lockout plunger at all, it sounds to me like you need to adjust the coupler forward a tad.

When you suggest adjusting the coupler forward do you mean lengthen the overall linkage? I would normally do this by loosening the 13mm clamp and pulling back on the shifter lever.

Thanks

[gtc]

Yes, exactly.
Make a mark with a sharpie to see how much you are moving the shift rod clamp.

[OldSpool87]

Originally Posted by gtc

Yes, exactly.
Make a mark with a sharpie to see how much you are moving the coupler.

Thanks GTC.

If the other gears are engaging well, I understand it that there is no clockwise/counterclockwise adjustment to make?

[gtc]

Correct.

I'm sorry, I spaced and was thinking of the shift rod clamp. The coupler stays on the transmission shift rod and does not move during adjustment.

[NZJimmy]

Glad I came across this thread! Not hijacking but I have a similar issue with 5th to 4th engagement. All other gears are fine and can go into 4th from 3rd, it's just the way down that there's an issue. I only have wevo psj, wevo clamp, seine and factory short shift (not wevo shifter-this was going to be next) and have been really battling with coupler adjustment (thinking it was this) as if I change I then battle with other gears-make further adjustment and it's back to 5/4 issue again! I'm going to now try the clamp adjustment only as suggested here (after making a mark with current location) to see if this works. Thanks for the info all and good luck with your adjustments!

[Mahler9th]

There are various ways folks use to adjust the various types of couplers out there. The more you do it, the easier it gets. Patience can be helpful.

Wevo have great instructions, as did SRP back in the day.

I was a fairly early adopter with a Wevo shifter and coupler back in 2002. Love the products... but need to disclose that I consider WEVO friends. The Wevo principal designer has many, many years of pro racing technical experience-- for us PCar folks, most notably with the Brumos team when they ran DP's.

Be aware that you can buy a Wevo spring kit if you want to do some fine tuning. I did so more than a decade ago and it worked out really well. About $40.

You can also buy a Wevo clamp (and I think there are others now as well). I have the Wevo clamp and it made a difference for me.

[OldSpool87]

Originally Posted by Mahler9th

There are various ways folks use to adjust the various types of couplers out there. The more you do it, the easier it gets. Patience can be helpful.

Wevo have great instructions, as did SRP back in the day.

I was a fairly early adopter with a Wevo shifter and coupler back in 2002. Love the products... but need to disclose that I consider WEVO friends. The Wevo principal designer has many, many years of pro racing technical experience-- for us PCar folks, most notably with the Brumos team when they ran DP's.

Be aware that you can buy a Wevo spring kit if you want to do some fine tuning. I did so more than a decade ago and it worked out really well. About $40.

You can also buy a Wevo clamp (and I think there are others now as well). I have the Wevo clamp and it made a difference for me.

Thanks Mahler- I installed their clamp when I did the PSJ. I ordered a set of springs the other day hoping this will give me some additional adjustment options.

[tobluforu]

Same thing on my rennshift, if everything is fine shifting wise, it's the forward/aft position of the shifter. Drove me nuts for weeks, then finally after adjusting it probably 25 times, bingo.

[rfloz]

Originally Posted by NZJimmy

Glad I came across this thread! Not hijacking but I have a similar issue with 5th to 4th engagement. All other gears are fine and can go into 4th from 3rd, it's just the way down that there's an issue. I only have wevo psj, wevo clamp, seine and factory short shift (not wevo shifter-this was going to be next) and have been really battling with coupler adjustment (thinking it was this) as if I change I then battle with other gears-make further adjustment and it's back to 5/4 issue again! I'm going to now try the clamp adjustment only as suggested here (after making a mark with current location) to see if this works. Thanks for the info all and good luck with your adjustments!

I was having this issue after the WEVO shifter installation, i.e., the 5-4 downshift was balky at best.

It went away after I re-learned to shift! If I pulled the lever straight back from 5th it hit the detent, as expected. If I pulled the lever hard to the left it wouldn't go into 4th. Solution - pull the left moderately lefit and it goes right into 4th. Doh!

BTW - I did the whole deal - WEVO shifter (tall knob), PSJ coupler, all new bushings and even motor and trans mounts. Yes, it shifts much better. But, be aware all this will not cure worn sychros. Still a PITA down shifting into 2nd sometimes and into 1st unless the car is fully stopped.

So, you may not need an adjustment to the shifting parts, but maybe adjust the driver.

Good luck.

[OldSpool87]

Would a forum member be able to help me better understand exactly what causes the grind on the 5-4 shift? I found the video below very helpful in understanding the internals of the 915. However it does not specifically cover the 5-4 shift and I’m having a hard time visualizing it.

https://youtu.be/jcm7EIrA_3w


Sent from my iPhone using Tapatalk Pro

[KTL]

A grind on a 5-4 shift is often because you're touching reverse. That's not good.......

[OldSpool87]

Originally Posted by KTL

A grind on a 5-4 shift is often because you're touching reverse. That's not good.......

Right, but what exactly is touching? The dongle which engages the shift fork?

Thanks

[KTL]

Nope it’s not the shift fork or the dongle that steers it

It’s the actual shift sleeve that’s shared by 5th and reverse. Remember that 5th and reverse are in the same shift plane so they share a sleeve just like 3rd and 4th do, as do 1st and 2nd. However, 5th-R sleeve is sorta of odd in that it has large bullnose teeth on it to engage reverse. As you’re coming down from 5th, the reverse side of the sleeve is moving toward the the double-geared reverse idler. If you go too far down with your shifter movement (or you don’t have good clearance inside the trans) before you make your movement to the left toward 4th, you can touch reverse. That’s the whole purpose of the reverse lockout teardrop/pawl on the factory shifter which blocks you form entering reverse and guides you over to fourth

So it can also be a shifter thing. If the WEVO setup you have right now is adjusted in a manner that allows you to touch reverse before being blocked by the reverse lockout plunger, then it would seem you need to adjust the coupler connection by moving the shifter lever a bit rearward from neutral to reduce the amount of “throw” you’re getting with the downward movement of the shifter

[jjeffries]

Excellent explanation Kevin! Best, John

[OldSpool87]

Originally Posted by jjeffries

Excellent explanation Kevin! Best, John

I’ll second that and really appreciate the thoughtful response.

Can I confirm then that moving the shifter rearward from neutral would be the same as lengthening the linkage?

Again, many thanks.