Gearbox issue, Am I in for a rebuild? Options

[TRS63]

Hello all,

I think that my gearbox might need a rebuild but needs confirmation for you all with more experience (IMG:style_emoticons/default/smile.gif)

First, the facts:
-car is my 1974 1,8l, side-shift gearbox, total mileage unknown, no bill about any rebuilt.
-Short shift from Martin Bott in it since ~3000kms, adjustment fine, never had issues.
-all bushings are 2 years/5-6000kms old so quite new
-Gearbox-oil is ~2500kms/8 months old

The issues I encounter:
-since I own it, it NEVER was possible, from 2nd to 1st to downshift while the car is rolling (by impossible I mean impossible without huge grinding).. The PO told me at that time that it is like that with all 914s, never checked and trusted him but unsure now (IMG:style_emoticons/default/unsure.gif) (IMG:style_emoticons/default/unsure.gif) is it true? (IMG:style_emoticons/default/confused24.gif) Since I own it I always put first only with the car not rolling, otherwise stayed in 2nd gear. .if the car is not moving, no issue at all putting first gear (or reverse), no grinding,..

-since the last 2 rides (40kms?), I have grinding issues putting the 2nd gear downshift or highshift. Increased and at the beginning I thought it was when the car was cold, now I don't think so and it happens every ~2 of 3 shiftings (IMG:style_emoticons/default/sad.gif)
3-5th gears are absolutely fine. And as I can select them fine and without any issue, I assume clutch and shifter setting to be fine, do you agree ?

-it seems to be a couple drop under the gearbox, but nothing big. Can't think that a small leakage could cause such issues, what do you think?

My plan:
-put the car on the lift, check every bushings and linkage adjustment
-if I see any issue: bushes, leakage,... I will fix it and try
-if good..Happy me (IMG:style_emoticons/default/cheer.gif)
-if not..gearbox out and rebuild (IMG:style_emoticons/default/sad.gif)

What are your thoughts on my issues?

Thanks

Antoine

[peteinjp]

Defiantly refresh any linkage issues- makes a huge difference in usability.

But your issue sounds similar more like the clutch is not fully disengaging. Check that adjustment first if you have not already.

Pete

[TRS63]

Oops, forgot to mention, all bushings are 2 years/5-6000 kms old..so should be ok.. but will check them!

Antoine

[930cabman]

Defiantly refresh any linkage issues- makes a huge difference in usability.

But your issue sounds similar more like the clutch is not fully disengaging. Check that adjustment first if you have not already.

Pete

(IMG:style_emoticons/default/agree.gif) I would check clutch adjustment first, even go a bit past where you might normally go with the adjustment. So far as leakage, look at the speedo drive and selector shaft, both reasonably easy fixes. This also assumes the linkage is in order.

[TRS63]

Thanks, I will check it as a first!

One thing I feel unsure: how does a clutch adjustment could affect only the 2nd gear and not the others?

Thanks

Antoine

[rhodyguy]

Difficulty in R AND 1st?

[TRS63]

No! The first gear comes without grinding only if I am not rolling but always was the case.. (but should it be like that?)

[rhodyguy]

I have never attempted to put the trans in 1st while moving. (IMG:style_emoticons/default/confused24.gif) Try engaging 2nd before going to 1st.

[Cairo94507]

You should be able to select 1st gear while rolling to a stop or going slow- I can. Good luck, Michael (IMG:style_emoticons/default/beerchug.gif)

[brant]

Tighten your clutch

[mgphoto]

There is no syncro between 2nd and 1st for down shifting. You cannot power shift, you must idle and align the dogs to engage without clash.
A number of 901 gear boxes have difficulty shifting to 1st at a standstill, a little bit of roll helps the dogs to engage.
Up shifting with gear clash 1st to 2nd might indicate a rebuild, down shifting 3rd to 2nd with gear clash is a strong indication that you need new syncros. Shifting from neutral to reverse with gear clash is usually a clutch problem. Your issue is probably clutch adjustment related, your clutch needs to be adjusted perfectly to determine if the gearbox is at fault.

[NARP74]

While you are checking things, look at your pedal board too. Sounds strange but mine did not have the correct hardware and started to move around. Then I found the clutch adjustment was not correct after that was sorted. Then I found some hardware was missing at the clutch end too. After chasing all of that it got better. Look at them as a whole system and go through all of it.

[TRS63]

Thanks a lot for the support !!

I won't have access to a lift until tomorrow evening but I just slide myself under the car and tightened the clutch (which looked a bit loose) and checked the bushings. All are looking good..but the "pointy screw" holding the two selection bars together at the joint near the firewall was a bit loose! So I also fixed it.. I will do a short test drive tonight, I will keep you all informed on the result !

Bests

Antoine

[dr914@autoatlanta.com]

grinding with a loose clutch cable occurs first at a standstill in first reverse and then as it worsens the higher gears

no grinding in first and reverse at a standstill, but rolling downshift into first means first gear is bad (dog teeth and slider


HOWEVER check the transmission oil level first 80/90 weight


rare instances, the clutch disc is beginning to shatter, or the pressure plate is cracked

Hello all,

I think that my gearbox might need a rebuild but needs confirmation for you all with more experience (IMG:style_emoticons/default/smile.gif)

First, the facts:
-car is my 1974 1,8l, side-shift gearbox, total mileage unknown, no bill about any rebuilt.
-Short shift from Martin Bott in it since ~3000kms, adjustment fine, never had issues.
-all bushings are 2 years/5-6000kms old so quite new
-Gearbox-oil is ~2500kms/8 months old

The issues I encounter:
-since I own it, it NEVER was possible, from 2nd to 1st to downshift while the car is rolling (by impossible I mean impossible without huge grinding).. The PO told me at that time that it is like that with all 914s, never checked and trusted him but unsure now (IMG:style_emoticons/default/unsure.gif) (IMG:style_emoticons/default/unsure.gif) is it true? (IMG:style_emoticons/default/confused24.gif) Since I own it I always put first only with the car not rolling, otherwise stayed in 2nd gear. .if the car is not moving, no issue at all putting first gear (or reverse), no grinding,..

-since the last 2 rides (40kms?), I have grinding issues putting the 2nd gear downshift or highshift. Increased and at the beginning I thought it was when the car was cold, now I don't think so and it happens every ~2 of 3 shiftings (IMG:style_emoticons/default/sad.gif)
3-5th gears are absolutely fine. And as I can select them fine and without any issue, I assume clutch and shifter setting to be fine, do you agree ?

-it seems to be a couple drop under the gearbox, but nothing big. Can't think that a small leakage could cause such issues, what do you think?

My plan:
-put the car on the lift, check every bushings and linkage adjustment
-if I see any issue: bushes, leakage,... I will fix it and try
-if good..Happy me (IMG:style_emoticons/default/cheer.gif)
-if not..gearbox out and rebuild (IMG:style_emoticons/default/sad.gif)

What are your thoughts on my issues?

Thanks

Antoine

[bugat5speed]

Hi,
there is of course a synchro for downshifting into 1st gear. You only need it for downshifting, what else for? If you shift into 2nd from 1st the synchro unit of the 2nd gear does this job!
You must be able to shift from 2nd to 1st whilst still driving about 20 km/h. That requires good synchro unit. If I write good synchro unit I mean synchro ring, synchro sleeve and also dogteeth.
Nice to hear that you use my shifter!!! Thanks for buying it.
If you need some more info about the problems with the gearbox, feel free to call me.
Martin Bott
Bott Fahrzeugtechnik
www.bott-fahrzeugtechnik.de
Instagram: bott_fahrzeugtechnik

[RoadGlue]

You should be able to select 1st gear while rolling to a stop or going slow- I can. Good luck, Michael (IMG:style_emoticons/default/beerchug.gif)

Agreed on this. Right as you're about to come to a stop, but while rolling, you should be able to slip it into 1st.

[DRPHIL914]

Defiantly refresh any linkage issues- makes a huge difference in usability.

But your issue sounds similar more like the clutch is not fully disengaging. Check that adjustment first if you have not already.

Pete

Tighten your clutch

You should be able to select 1st gear while rolling to a stop or going slow- I can. Good luck, Michael (IMG:style_emoticons/default/beerchug.gif)

Agreed on this. Right as you're about to come to a stop, but while rolling, you should be able to slip it into 1st.

(IMG:style_emoticons/default/agree.gif) i agree with all of these, and i just had this issue this past weekend, and it was that the clutch was not fully disegauged as either the newer cable was stretched or the nuts had loosened slightly since i just put the motor and transmission back in the car 2 weeks ago. I was having a heck of a time trying to get it into gear from neutral even with pedal to the floor, and just barely letting it out it was already moving forward. Tightened up the cable a bit and immediate difference was felt and no issue with grind going into 1st from second.
i would ask, how far out do you let the clutch pedal before it starts to engage and move if you are sitting flat and stopped? I think it should be about 1/4 of the total travel before you feel that happen.
Phil

[TRS63]

Hi,
there is of course a synchro for downshifting into 1st gear. You only need it for downshifting, what else for? If you shift into 2nd from 1st the synchro unit of the 2nd gear does this job!
You must be able to shift from 2nd to 1st whilst still driving about 20 km/h. That requires good synchro unit. If I write good synchro unit I mean synchro ring, synchro sleeve and also dogteeth.
Nice to hear that you use my shifter!!! Thanks for buying it.
If you need some more info about the problems with the gearbox, feel free to call me.
Martin Bott
Bott Fahrzeugtechnik
www.bott-fahrzeugtechnik.de
Instagram: bott_fahrzeugtechnik

Hi Martin,

Thanks for the information. I definitely can't shift from 2nd to 1st whilst driving above 2-3km/h so there is an issue there for sure.
I will certainly come back to your offer and call you.
Concerning your shifter, I already told it in my build thread but that is certainly the best thing I bought for my 914!! The feeling, the position closer to the steering wheel, the quality and look (without the leather bag!), I just love it !

To all: thanks a lot for the support.

Clutch cable tightening yesterday did not bring the expected, still grinding 1-2 or 3-2, even if a bit less often. I will check everything again tonight and keep you informed!

Antoine

[Van B]

I had that issue when I bought my car. It was bushings. Especially the bush on the transmission. Also, realized that going from 2nd to 1st needs to be steady pressure while the car is slowed down to a steady jogging speed. Any faster and it will bind.

[Van B]

@TRS63
Would you mind adding your car info to this thread?
http://www.914world.com/bbs2/index.php?s=&...t&p=2969526

Is your car an original German spec or a US import?