312d auto slow and noisy

[Mbmotorhome]

Hi Guys.
Im new to the group.not new to mercs tho.
Ive recently bought a motorhome based on a 312d sprinter chassis.
Its a old 1 but in good nick.
Its on a R reg 1997.
Its got the 2.9 5 cylinder turbo engine with the mercedes sprint shift auto box.
It pulls really well.
Only issue is its under geared.
At 60mph its on 3000rpm which makes the drive loud and slow.
I wondered does anyone know can a diff or axle from a later sprinter be fitted to increase speed and lower engine revs??
Ive made a few enquiries with diff repair companys around the uk but have drawn a blank as know 1 seems to know.
And mercedes cardiff never got back to me with the same enquiry?
Thanks

 

[a111r]

Welcome. Probably best to also join the Sprinter forum and ask on there?

 

[BTB 500]

I know the W639 Vito came with four different back axle ratios from 3.727 up to 2.923 (depending on the engine). I would expect the Sprinter to be similar, but I agree you will probably get more/quicker replies on a Sprinter forum.

 

[91dm]

I can see on the parts cat there's a few different ratios listed for a 312 D. I'm surprised a diff repair place can't help you out. I'd need to know the chassis number to check what you have or could change to?

Some listed for 312D

35 A6023502639 Replaced By: A9033500439 RING GEAR AND PINION 34:7
35 A6023502739 GEAR SET DIFFERENTIAL GEAR,RATIO: 37:7
35 A6023502839 GEAR SET DIFFERENTIAL GEAR,RATIO: 37:6
35 A6023502939 GEAR SET DIFFERENTIAL GEAR,RATIO: 37:9
35 A6683500439 Replaced By: A6683500739 - RING GEAR AND PINION
35 A6683500739 Replaced By: A9033530610 RING GEAR AND PINION DIFFERENTIAL GEAR,RATIO: 3.7272 (41:11)
35 A6683500839 GEAR SET DIFFERENTIAL GEAR,RATIO: 36:11

 

[Mbmotorhome]

I can see on the parts cat there's a few different ratios listed for a 312 D. I'm surprised a diff repair place can't help you out. I'd need to know the chassis number to check what you have or could change to?

Some listed for 312D

35 A6023502639 Replaced By: A9033500439 RING GEAR AND PINION 34:7
35 A6023502739 GEAR SET DIFFERENTIAL GEAR,RATIO: 37:7
35 A6023502839 GEAR SET DIFFERENTIAL GEAR,RATIO: 37:6
35 A6023502939 GEAR SET DIFFERENTIAL GEAR,RATIO: 37:9
35 A6683500439 Replaced By: A6683500739 - RING GEAR AND PINION
35 A6683500739 Replaced By: A9033530610 RING GEAR AND PINION DIFFERENTIAL GEAR,RATIO: 3.7272 (41:11)
35 A6683500839 GEAR SET DIFFERENTIAL GEAR,RATIO: 36:11

Thanks for that
Chassis No is
WDB9034122P674956

 

[91dm]

Hopefully this might help:



I know on a car diff the number is usually stamped on the casing.