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View Full Version : Sprintshifter grinding 2nd to 3rd


Mozz
05-23-2015, 10:14 AM
Hi all, it's been several years of trouble free use with my 316 after replacing the pump many years ago with the help of a few of you chaps, but this week I've started to encounter a small grinding when shifting auto or man from 2nd to 3rd, and same happens on down shift. It's a typical worn syncro type noise, but I thought here was the best place to ask. The same thing happened briefly many years back, only for a morning with a heavy load, and it's happened once or twice when it was cold, well cold as it can get on the north coast of NSW (Oz), but it's never persisted. This week is different. I found a old thread with same issue but it ended without an outcome. Any ideas?

NORTON
05-23-2015, 12:48 PM
MB Star diagnosis can perform a Clutch teach which resets the clutch take up point caused by wear of the clutch disc, and also a Gearbox teach which I believe can adjust the selector fork travel controlled by the valve body which may be applicable in your case.
I haven't any experience in the Gearbox teach but it may be a possibility if these haven't been done recently.
Unless you have access Star Diagnosis it will require a dealership or a workshop that specialises
in European vehicles. I had mine done by a Bosch high end diagnostics machine.
Basic checks of the oil level in the gearbox and Sprintshift reservoir may be needed but any oil leaks would be noticeable under the gearbox and would more than likely effect other gear selections

MercedesGenIn
05-24-2015, 10:04 PM
Hi there,

Not sure if this is the 6 speed Sprintshift gearbox, it is internally the same animal in both the manual and automated selection versions, the syncros and gear-train are the same and susceptible like most everything, to wear over time. (I suppose if it is an earlier version the same controls apply as it is really just a manual gearbox with added complexity)

If this is not the exact gearbox i do apologise. We don't see these often in the UK, Supermarket delivery van fleets seem to have a long standing liking for them and I understand some health service transportation vehicles, there are some VW/Audi derivatives fitted to passenger cars. However the same rules should apply.

Clutch actuating pump dwell adjustment could improve things as Norton says with a dealer teach, but as this has the same pressure dwell for all in-motion selections I wouldn't bank on that being your complete answer. (there is feedback provided from the clutch slave cylinder via means of a position sensor, so its plate position is known by the controller and compensated for wear) The gearbox selector actuators only push/pull/twist to a detent in all cases so really as you say you have it 'on 2-3 up and 3-2 downshift', I doubt this is the root problem either, unless there is a developing issue with the actuator that controls rotation of the selector shaft involved in the shift (2-3) which I would image would be a pull and twist.

Just as Norton recommends above, I would have a look at the gearbox from underneath, look for hydraulic leaks and general condition of the assembly. You may wish to try the simple cheaper stuff first - check the gear oil level, even change the gear-train oil for a slightly lighter weight. The Hydraulic control oil is separate to the main gearbox oil, gear oil that is easily accessed through traditional drain and fill plugs.

Here is some general reading on oil type selection found to make improvements on Vito and Sprinter boxes and what may benefit your problem (or not! - but worth a go) http://www.mercedes.gen.in/WP35/poor-first-gear-selection-manual-gearbox-problem-w639-vito-cure/

Have a read of this too if you want to know how the 6sp version all works, principles the same over all MB/VAG automated manual g/boxes apply: http://www.volkspage.net/technik/ssp/ssp/SSP_372.pdf

Hope that helps
All the best
Steve