G’day,
I bought an ex MTT bus in May which has already been converted into quite a nice motor home. My problem is in identifying the various components as I cannot seem to find a set of specs, nor anyone who knows how to get in touch with the appropriate section of MAN.
My immediate problem concerns identification of thegearbox and diff. The first for servicing instructions and the second so that I may mount a search for a higher ratio. I’ll deal with each problem separately.
I think the gearbox is a ZF 14HP500 being a four speed auto with a manual shift by way of a line of buttons on the dash marked 1,2, D, N and R. Can anyone confirm this for me or point me in the right direction?
The differential is very low ratio. My research says that it may be 4.63. A 3.36 option exists but there appear to be no parts in Oz. The 4.63 has the engine doing about 2000 rpm for 70kms. While I am happy with the speed and climbing ability, other road users have indicated some displeasure and the excessive revs can’t be good for it. I would think max torque is at about 1500rpm.
I have held a heavy combination licence for over 50 years but have driven very few big rigs since I was 18 so I am also looking for advice on operation of the auto gearbox. It has an added extra which is supposed to drop down through the gears as one decelerates. However I can’t seem to hold 2 or 3 on a hill and it insist on changing up with consequent higher wear on the brakes.
Looking forward to having a chat. Thanks in advance. I have just returned from 5 months and 7000 kms on the Big Island but please treat me as the amateur I am.

Simon

Simon Firth wrote:G’day,
I bought an ex MTT bus in May which has already been converted into quite a nice motor home. My problem is in identifying the various components as I cannot seem to find a set of specs, nor anyone who knows how to get in touch with the appropriate section of MAN.
My immediate problem concerns identification of thegearbox and diff. The first for servicing instructions and the second so that I may mount a search for a higher ratio. I’ll deal with each problem separately.
I think the gearbox is a ZF 14HP500 being a four speed auto with a manual shift by way of a line of buttons on the dash marked 1,2, D, N and R. Can anyone confirm this for me or point me in the right direction?
The differential is very low ratio. My research says that it may be 4.63. A 3.36 option exists but there appear to be no parts in Oz. The 4.63 has the engine doing about 2000 rpm for 70kms. While I am happy with the speed and climbing ability, other road users have indicated some displeasure and the excessive revs can’t be good for it. I would think max torque is at about 1500rpm.
I have held a heavy combination licence for over 50 years but have driven very few big rigs since I was 18 so I am also looking for advice on operation of the auto gearbox. It has an added extra which is supposed to drop down through the gears as one decelerates. However I can’t seem to hold 2 or 3 on a hill and it insist on changing up with consequent higher wear on the brakes.
Looking forward to having a chat. Thanks in advance. I have just returned from 5 months and 7000 kms on the Big Island but please treat me as the amateur I am.

Simon

I may be able to help as a MAN owner I managed to get a Factory Motor repair manual on all MAN motors from Germany. I also have manuals on MAN buses PERHAPS I CAN HELP
GUY ARAB

Gearbox would be a ZF-Ecomat 4 HP 500, possibly with Neutral at Bus Stop function. It's a very common city and intercity bus gearbox.

Engine is a 6.596-litre 6-cylinder, model D 0826, either TOH (turbocharged only) or LOH (turbo & intercooled). It is an engine that loves revs, being happy to work at up to 2500 rpm. Power (and therefore torque) is low until around 1200 rpm. It's not an engine that enjoys burbling around at low revs. A taller diff ratio would put a severe dent on the already marginal acceleration as well as adversely affect gradeability and performance with a full payload.