Time to go from 1st to 2nd in manual transmission

[ghenne]

I have a '65 230SL with a manual transmission. Taking it for a spring drive, I noticed I have to wait about 3 seconds before putting it into 2nd from 1st. I was thinking how much quicker the car could accelerate from the light if this time were shorter.

How long should it take? What can be done?

[GGR]

Oh! By reading the title of your post, I thought you had been driving your car in 1st only and that you were now ready to start driving it in 2nd!

Could you describe more in detail what happens when you try forcing it shift faster?

It could be a clutch related issue (or its actuation) or a transmission issue (wrong oil or worn synchro).

Is the problem more noticeable when the engine/transmission are cold?

[Cees Klumper]

I read George's post to mean that the ratio of the first gear is too long, meaning before he has the engine turning enough RPM's for it to make sense to shift to second, 3 seconds pass by. With a shorter ratio, the car would accellerate quicker and second gear would also arrive faster. But I could be wrong.

[GGR]

It could be understood like that too, though these MB trans are notorious for having a very short 1st. May be the rear axle was swapped for a 3.27, which on a 230 could indeed translate into what you describe?

[ghenne]

It's the from when the engine has sufficient revs and I engage the clutch, until I can put the gear lever into 2nd. If I rush it, I grind the gears.

[tel76]

From what you are describing a re-build of the gearbox is required, the synchromesh on that gear is badly worn, if you do not want the expense of a rebuild you could delay the inevitable by double de clutching and put up with a slow gear change.

[GGR]

Looks like a synchro, indeed. Before a rebuild, try replacing the oil. These trans take ATF. Often mechanics put standard gear oil in there and the result can be a notchy shifting. ATF is more fluid so the synchro may grab the gear better. Worth trying before taking everything apart.

The other issue could be that your clutch actuation system is not working properly. If you have an internal leak in the master or the slave cylinders, or if you have air in the circuit, the clutch won't disengage 100%. It could also be the adjustment between the slave cylinder and the yoke. Symptom is also grinding while shifting, and difficulty to engage first with the engine running and car at a standstill.

[George Des]

Yes sounds like gear oil was put in the tranny. I made this mistake many years ago on my ZF-5 Speed and that was exactly the result.

[ja17]

Does your speedometer needle jump during deceleration and fall for a second during acceleration?

[A Dalton]

 Agree with JA..

This would be first suspect on W113 manual trans syncro  complaints.

http://classicmotorsports.com/project-cars/1966-mercedes-benz-230-s/a-cheap-fix-for-our-transmission/

[Cees Klumper]

Welcome back Arthur!

[Benz Dr.]

Yeah, but I would have checked the oil in the trans for level or ATF when it was here two years ago so it's more likely to be any number of small factors that relate to age and wear.
What I have found during almost every rebuild is exsessive end play on the input shaft. It should be nezxt to .000'' but is often .030'' or more. That alone will cause the syncros not to work as well as they should. If it grinds going into any one gear ( up or down ) it will be that syncro but a lot of end play tends to make it much worse.

[ghenne]

Does your speedometer needle jump during deceleration and fall for a second during acceleration?

No - it behaves properly.

[ja17]

OK ghenne,  Sometimes shifting problems occur when the slotted nut on the tail shaft becomes loose. But, when this happens, the speedometer becomes a little erratic also.  Check the cheap thing first, like the fluid and the clutch adjustment.

Nice to hear from you Arthur!

[ghenne]

Thanks to everyone for your input. I'll report back on the solution!

[ghenne]

Update: my mechanic pulled the transmission and had a look inside. Clutch looks fine, no metal parts in the oil.

Uh oh. 3 teeth missing on 1st to 2nd, 2 on 2nd to 3rd. The synchro rings are made of soft brass and are worn.

Any advice on replacing the synchros?

[ghenne]

Here's a picture of my old transmission: 50 years old, 250,000 km. The synchro rings (the brass ones in the picture) are significantly worn and have about 1cm of play, both of which will contribute to the slow shifting I was experiencing.

We found a rebuilt transmission (thanks, Benz Dr!) and we'll have it in this week.

[ghenne]

The rebuilt transmission is in and the car is back home. Shifting is now tight and accurate, with no grinding. It feels great!

Thanks to Benz Dr. for a great rebuild!