What do I do about 2nd gear grinding ?
 

My yellow 74 240d (cabbie) manual 4 spd grinds when shifting to 2nd gear. If I wait a second in netural with clutch pressed then shift to 2nd then it does not grind.
My options I think:
1. live with it.
2. fix the transmission if that is possible.
3. change transmission from a recycler.
4. Change transmission oil, will that make any difference ?
5. ??? any ideas ?
Which option makes more sense?
I am thinking of trying option 4 first to see if that makes any difference.

You are on the right track... change the oil but don't expect a drastic improvement, it may help marginally or not at all.

Chances are you'll be stuck with option #1, live with it and shift slower. Basically your 2nd gear synchro is shot and it's not cheap to have it fixed. I'm sure the parts aren't too bad if you do it yourself, but that requires a lot of time and probably tools you don't have. You probably knew all of this already, sorry man.

It's not unusual at all, probably one of the most popular maladies after loose steering or rough idle or a poorly shifting automatic.

Now's a great time to teach yourself how to double clutch though.

You could always try to start out in second.....

Jim

OK will try that too as well as going from 1st to 3rd.

Definetly trans is not a DIY for me.

What oil does Mercedes recommend? I had a 1980 that called for automatic transmission fluid. It had gear oil in it when I got it, and it would grind when I shifted into both second and third. Unfortunately, the fill plug on the transmission was stuck, and I was unable to replace the fluid myself. I went to several shops (not the dealer) and they refused to change the oil to ATF - said they'd never heard of such. I finally went to a Jiffy Lube and the guys there were willing to do whatever I told them to, so long as I signed the work order.

Putting in the ATF eliminated all the shifting problems, and also made the transmission much, much quieter. I don't know what was recommended for your car, but if it was ATF, a change might fix your problems.
John

The Oil most likely would be manual transmission oil and sometimes gear oil (diff oil). I have never heard of putting ATF in manual transmission. ATF has a lot lower viscosity, I do not know if that is better or worse for worn out syncro. The difference between manual tranmission oil and gear oil is that gear oil has tons more antiwear and extreme pressure (EP) additives. These additives in large amounts may hurt the more delicate components of manual transmission. First I am going to try Royal Purpule Synchromax oil.
Attached is comparison of properties of different oils.

ATF type "F" is indeed what is recommended for your manual transmission. Dexron III will work as well.

I put ATF in mt 1976 240D manual transmission it works as it should. And this is what should be in there.

What type of ATF did you use?

Type F is Ford type not applicable to cars that require Dexron series or Mercon type fluid.

the mercedes service manual says to use type A
i think i used Dexron III Valvoline. I am at work, when i get home i will check to see what i used.
If everything is worn out i was told to use gear oil.

From my experience in a W123, gear oil is absolutely the wrong thing to use with a worn tranny. I don't think it really matters what ATF you use in a manual. Modern ATF is different than the ATF in the 70s anyway.
John

Follow whatever your manual says. My MB needs ATF in the manual transmission. My MGB needs 20W50 per factory specs. And my MGBGT V8 has hypoid SAE 90 oil as far as I recall. My point is, read the manual and don't second guess.

Bert

Yes, that advice would nice be in ideal conditions. I am not in ideal situation.
The car is ~ 35 years old and synchro is messed up. Fluids recomended in the manual may no longer be avaialble, If I knew what it said, manual is not available. I am calling on the forum memebers to tell me their experience in this area.

The different types of ATF are formulated for automatic transmissions. It's not critical to use exactly what is specified in a manual transmission. As already recommended use Dexron III, since type A is no longer sold.
Changing the oil is easy and cheap. You could bleed the clutch hydraulics while you're down there also.

I'll try one last time. If the manual says ATF, use ATF. The tranny may well not be worn out - the synchro may be working improperly because you have oil that's too heavy. That's what was wrong with mine. Change to whatever ATF you can find and see if it helps. Otherwise, go ahead and spend a lot of money on a transmission.