W460 300GD auto - torque capacity
I am rebuilding a 1983 model which, when new, was fitted with an aftermarket turbo (a common mod here in Australia). I expect this engine will be capable of say 240Nm. I have read somewhere that the auto box of this era (722.1xx) was rated at 200Nm.
As I may want to tow a 1T trailer up hills and down dales, does anybody have any experience as to the torque capacity of these boxes. Are they over-designed like the OM617 and thus capable of being ''overloaded''?
Your comments please!
Adrian
Hi the performance of the normally aspirated OM617 mated to the 720.1 series g'box (which was all there was in 1983) was dismal!! adding a turbo with intercooler and wide bore exhaust without changing the injector pump enhanced the perfomance by 15%..adding the OM617A injector pump gives you another 10%...bearing in mind that the OM 617A was the peak perfomance engine in the OM 617 range and it uses different pistons to the OM 617 basic engine... adjusting the throttle pedal linkage to ensure maximum movement of the injector pump rack helps.and playing with the wastegate gets you more boost but not before the engine reaches 1200rpm...pulling more than 1000kg will cause the gearbox to hunt on hills as the engine rpm drops and loses turbo boost.....you get used to flexing the right foot to help smoothe the gear changes......
I don't know anything about horses other than they are quite stupid four-legged animals.
What I do know is that the automatic gearbox fitted to the 300GD imported into Australia in the early eighties is not dissimilar to the gearbox fitted as standard to the W123 300 TD Turbodiesel powered by the OM617A, which is the best you can aim in terms of power and torque by adding an aftermarket turbo to your engine.
I'd be much more concerned if my G had the 5-speed Getrag manual instead....
Well here is some information from another Forum. Here it says that my G has the 722.1 (W4A018) good for 180Nm. I wonder if it can be upgraded to the capacity of the W4B025 which presumably has a similar casing. The reason I ask is that my box needs a rebuild anyway, so I'd like to do the job properly and uprate it if necessary or indeed possible. Thanks for any input.
Cheers
Adrian
Torque capacity
The designation W4A0xx tells us the maximum input torque in kpm (kilopondmeter).
1kpm=7.23lb/ft.
722.0 (W3A040)- 290lb/ft
722.1 (W4B020 or W4B025)- 145/180lb/ft
722.2 (W4B025)- 180lb/ft
722.3 (W4A040)- 290lb/ft
722.4 (W4A020)- 145lb/ft
722.5 (W5A030)- 216lb/ft
722.6 (W5A580)- 578lb/ft
G-models
720.1?x (W4A018)- 130lb/ft
722.39x (W4A028)- 202lb/ft
722.61x/63x (W5A330)- 216lb/ft (Used W5A580 in the larger engine models)
Source: contributor ‘forcedinduction’on SuperTurboDiesel forum
Hi the 722.394 / 398 W4A028 series G'box has the starter pad on the opposite side to interface with the M103 /M603 6 cylinder engines.it will not interface with the OM 617 .......
See the following link for reference of all the gearboxes fitted to the GWagen: http://www.4x4abc.com/G-Class/transmissions/getriebe.html
Yours must be 720.1?
See the following link for reference of all the gearboxes fitted to the GWagen: http://www.4x4abc.com/G-Class/transmissions/getriebe.html
Yours must be 720.1?
Over her in nZ I have one in my OM602 Turbo powered G and I have been towing a large Tandem braked trailer fi=ull of rocks about this hilly city and it changes well in fact better than when not under such a load.
Tanex, that is good to hear. I currently tow a campertrailer with a Disco Tdi auto, and this gearbox overheats in no time, despite new oil and improved airflow to the heat exchanger. Thanks for your feedback.
Tanex, that is good to hear. I currently tow a campertrailer with a Disco Tdi auto, and this gearbox overheats in no time, despite new oil and improved airflow to the heat exchanger. Thanks for your feedback.
Here it is at the top of a steep climb getting a load of rocks . Photo taken at noon today. But dont forget I am at 46 degrees South. G has A/C but have never used it. BTW the auto is a petrol 720.1. have a 722 5 speed which would like to go in but different length so am happy with just the 4 speeds
Yes ambient temperature plays its part. Tomorrow it is forecast to be 30degC here. By the way, your G looks very smart!
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fixwin38, thanks for your reply, it seems that I may be optimistic in the amount of torque this engine gives. What I want to know, really, is how the gearbox will handle extra torque and the duty of towing. I am hoping some folks have experience of towing horse floats and the like.