When to shift? Edit: Need to rebuild it??? Advice needed!

[SparksLP]

Hey all,
Is there a list somewhere that explains at which speed or RPM to upshift or downshift a stock bug transmission? Mine seems to be fine with upshifting. I usually go by sound and the little marks on the speedo, but it won't downshift into 2nd without grinding/catching unless I'm going about 10-15mph. Is this normal?

[Ol'fogasaurus]

Sparks, when the car is moving first gear should be the hard gear to down shift into assuming everything else is adjusted correctly. First gear has straight cut gears (assuming I remember correctly) and are not synchronized so it requires double-clutching along with the use of the "loud pedal" to get the trans and engine synchronized to the right RPMs in order to shift into first when the car is moving.

Not being able to shift into second with the car moving I would assume, assuming the trans is OK might be, that the shifter's s not adjusted correctly. The shifter's mounting plate is slotted to allow a bit of back and forth adjustment of the shifter. The shifter itself also could be worn which might not allow correct movement. There is also a bushing in the tunnel to support the shift rod that could be worn or the connector to the trans in the rear could be bad also.

I still double clutch when down shifting into any gear just because it is easier on components (or at least that is how I was taught more than 50 years ago ) and it keeps me mentally and physically in synchronization .

Check the adjustment first as it is the easiest and cheapest thing.

Lee

[Casting Timmy]

I'd look in the fill plug hole to see if the synchro is touching the gear or has a gap. Downshifting usually shows a worn out or broken synchro, the synchro isn't able to speed up the main shaft and clutch disc as it's worn out.

If it stays in gear and doesn't pop up, you could look into other stuff. If it just grinds on down shifting I would guess a worn out synchro first.

[SparksLP]

So theoretically it should downshift into second before I'm going that slow? I'm not crazy thinking something is wrong? When I get the chance I'll look in there and see what I see. And I'll check all the other things mentioned. Thanks!

[Ol'fogasaurus]

How are the transaxle mounts, all of them as they can cause problems when shifting also. Nothing is simple until you check, then rule out everything else before it's "geez was I…" .

Right now I am playing around with the transaxle mounts and shifter stuff and I was surprised just how easy it is to get the mounts (aka "pickle forks") to move up and down. One of the reasons for the Truss/Kaffer/traction bars which are just some, but not all, of the names for the same thing which is a design to hold the transaxle and engine mounts more ridged/in place when playing around. Remember the VW was not designed for what a lot of us are doing with the "li'l dears".

Lee

[Ol'fogasaurus]

Fun stuff:

Double clutching isn't a new thing but it has gone through phases... which often still crack me up. Double clutching was use for down shifting especially when you had straight cut gears and/or no synchro's in the trans. Basically you are matching the gear selection in the tranny using engine RPMs. "Deck shifting" is something different.

If you watch the movie "Bullet" during the chase scene where McQueen, in the '68 Mustang, is chasing the bad guys in the MOPAR you hear McQueen double clutching going UP through the gears not down through the gears as the concept was originally for. I seem to remember that there was a phase of this going on about in that time period but I never understood why. I think in the Elvis movie "Spinout" when the Cobra and the other full bodied race car are on the dirt track you hear some double clutching up gearing and the shifting of gears with no hand movement ( Bwahahahaha!).

Gear to engine RPM relationships are a good thing to learn but dam(n)age the trans learning it either: Chevies (et al: other GM products for example) from about the mid-50 and much later had clutch problems where the cross shaft from the chassis to the engine and transmission often would suddenly disconnect (usually trans or engine mounts or bolts) and leave the linkage "hanging". I once had this happen to me on the way home from work so I had to drive from the town I was working in, just south of Seattle, through Seattle using the main and down town streets to one of the suburb towns of Seattle, a distance of about 25 to 30 miles, without having the clutch pedal to rely on.. in "go-home from work" traffic. Timing stoplights and being able to shift using the throttle and shift lever along with a good battery came in very handy.

Lee

[SparksLP]

Adjusted the clutch a little and tried to readjust the shifter based on a Chris Vallone video, still clunking and grinding from 3rd to 2nd. Still need to check transmission mounts, but I'm thinking it's likely a synchro issue?

[SparksLP]

And as a follow-up question, roughly how much does it cost to get a transmission rebuilt, in case things are going bad?

[Ol'fogasaurus]

https://www.bing.com/search?q=the+cost+ ... 69c32cae5d

I think it also depends on just what is wrong but not too much in this life is cheap other than a hard time and it can range from free to OMG.

Lee

[SparksLP]

Ouch. I'll keep playing with settings and check my mounts, and pray to the VW God's that the transmission isn't crapping out, lol.

[SparksLP]

So, with all the adjustments and testing I've been able to do this far, all signs are pointing to my second gear synchro crapping out. So that sucks. If I'm going to have to get the transmission rebuilt anyway, might as well improve things. End goal for my car is to run autocross and eventually road race/track day type events, but still be able to drive around town. I can't afford a limited slip diff, but would a super diff be a good choice? And any changes to gears? Engine is going to stay 1600dp, but I'll eventually build up the internals for more power. Probably following SCCA HCS/HCR rules, since my local autocross club has a class that matches these rules. Thanks for any advice!

[SparksLP]

Time to dive back into the forums, need some advice.
Finally was able to get my transmission out and getting it ready for a rebuild. Any advice on things to have the shop change while they are in there? 1966 Bug swing axle hooked up to a 1600dp. I won't be building a motor for a while, but eventually I'll be adding more power. Assuming I don't get over 130hp from the future motor, and my rear tire sizes are between 205/5015 and 205/60r15, any reason to change the gearing or beef up the internals? Car will be used for a mix of street/autocross for now (hopefully track racing in the future). Thanks!

[Ol'fogasaurus]

Opinion... Generally inspect and replace gaskets, bearing and all the other components plus the case.

Street is the easiest build and I have heard opinions on the supper diff.

Autocrossing should be somewhat OK with a stock build but look into gear ratios too. when you get more power and re-set the VW up for more handling then gearing becomes more important.

The SCCA HCS/HCR rules probably require other changes but since you said that they match your autocross rules do it right the first time. I think one of the two Bruce's that post here should put his 2-cents in on this as I seem to remember that he is a trans guy.

Lee

[SparksLP]

Thanks. I'm thinking I'll go with a mostly stock setup for now and use money to fix other aspects. Stock transmission should be fine until I beef up the engine from the research I've been doing. Maybe do a super diff or stronger internal bits, but no gear changes for now?

[Ol'fogasaurus]

Thanks. I'm thinking I'll go with a mostly stock setup for now and use money to fix other aspects. Stock transmission should be fine until I beef up the engine from the research I've been doing. Maybe do a super diff or stronger internal bits, but no gear changes for now?

(Sigh), your probably right and... probably wrong this way but it is the way most of us go until we have made this same mistake too many times... then you may never get it finished either so your "damned if you do and damned if you don't"!

I've torn my blue buggy down to an almost bare chassis 3 times now to upgrade to what I have leaned. My black buggy is in the umpteenth start now and it is sitting there being looked at with things being moved around and other things being (fit) checked and it's getting ready to go back down again for more updates.

You are asking good questions so don't be afraid to do so, one of the reasons we are here. As I have said before... my opinion is worth slightly less than you paid for it.

Lee