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Discussion Starter · #1 ·
Hello everyone, i am a mechanic in australia and have been given the task of repairing a 300 G wagon, quite rare down under, i have searched and not come up with the info i require, but then again i dont know all the information as to its current specs.

the unit i am working on was a deisel with manual trans, it has undergone an engine swap and currently has the v8 and auto out of 450sel, the problem now is that the vehicle is revving quite high at 60 mph, we need to up the diff ratio from std, i am unsure of what they are now and won't know for a couple of weeks, i realize i can fitt biger tyres to up the ratio but the owner doesn't whish to do that.

what diff ratios are available? are they the same as any of the benz sedans? and where is some good sources to get them from? i dont mind second hand, i have to ship them a long way, price is probably the biggest factor.

thankyou in advance paul
 

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1980 240GD
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Tech specs for all models here:

http://www.g4rce.net/engl/models.html

Select the chassis type (460 or 463; dependent on the year of the vehicle) and then click the link for "Technical Data" under the 300.
 

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'80 230G SWB, '03 G500, '80 280GE LWB (sold), '98 Jeep Wrangler Sahara (sold)
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Before Dutch does his customary "ass-u-me" spiel, you'll have to let us know what g-type you have (460 or 463). This will better help us, help you.


GIINHESSEN - 2/2/2005 7:27 AM
Select the chassis type (460 or 463; dependent on the year of the vehicle) and then click the link for "Technical Data" under the 300.
The problem is that his vehicle is no longer a 300 but a 450, which means he needs to find higher gears (numerically lower). Not exactly sure about finding lower gears for a 460, but if it's a 463 i'm sure 500GE gears would be an answer.
 

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85 300GD 83 300TD
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Paul, Mike Serpe has some diff gears and may be able to help you. He will have an idea about what you will likely need in any case. The diffs in the trucks are not at all like the sedan setups with independent suspension. I don't think there is any parts interchangability there. The 463 front axles turn in the opposite direction to the 460 series so cannot be used because the gears are reversed. The transfer cases are different. The first three numbers of the vin are the series ID. Taller tires are the lowest cost solution to the problem. By far.

-Dai
 

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1980 LWB 280GE
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Don't have far to go.

The tag on the axle casing will tell what ratio was in there from the factory (and likely still is there). I think 300GD's came with 4.88 (listed on the tag as 4.9) gears stock, and unfortunately for you, that's the highest ratio MB offered for the 460s. Other ratios available were like 5.3 and 6.2:1.

Does the auto box in it now have an overdrive gear? If not, then your best bet would be to just get a fresh trans in there that has an overdrive.

As a point of reference, my 280GE has 4.9 gears and in 1:1 top gear in the trans, I'm turning a shade under 3,000 RPM (tach not super accurate, though speedo is calibrated to GPS) at 100kph on 235/85-16 tires. If you're seeing more revs than that, either you have lower axle gears (check the tag) or there's something wrong with the trans allowing slippage, or not getting to top gear.

If all is well with the components on hand and you still need to turn lower revs, I'd swap the trans for an OD model. If that's already done and revs are still too high, then you're left with bigger tires, or a complete axle and transfer case swap to a 463 setup that can get you, I think, a gear ratio in the 4.4:1 0r 4.1:1 range.

Good luck!

-Dave G.
 

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Discussion Starter · #6 ·
thanks for the quick replies, i will check out exactly which model the vehicle is, if in deed i am stuck for diff ratio's could i fit say range rover axles or something else in there with a different transfer case?
rangie axles and nissan patrol coil type axles are fairly easy to find here? or an OD auto out of anther model v8 benz sedan? if so which benz's had the OD auto?
 

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'82 300GD TD (Sold), '02 G500, '09 B200
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To my knowledge there is no auto tranny with an OD that will bolt up to that motor. There is, in fact, lower axel gears that will fit into 460 axels. I believe there is a ~4.3:1 and I know for sure there is a 3.73:1 (Steve Smith has them).

Hope this helps,
Steve
 

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1980 LWB 280GE
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Some specifics from the manuals

Check this thread:
http://www.benzworld.org/forums/forums/thread-view.asp?tid=188308&posts=21&hl=axle+ratio

Scroll all the way down to the last few posts in the thread. Harald posted some good info from the workshop manuals regarding which ratios could be fitted to which axles, and what the SA numbers were for each gear set. You still have to look at the axle tag to see which axle model you have, but to Steve's point, higher ratio (lower numerical) gearsets may be available for you.

When I get home I can try and convert some of the SA numbers (special equipment set) to actual ring and pinion part numbers. The electronic parts catalog was unfortunately for us, designed for dealers with a car in front of them to replace the original equipment parts for that vehicle, and not designed for us tinkerers to make modifications. Oh how I wish I could get the EPC to "list all R&P sets that fit 460s".[:)]

If we can get you some R&P part numbers then you'll just have to decide what ratio is in the car now and what change in cruising RPM you want and we can target the right new set.

The only bummer is that since the change is made in the axle, the bloke will take a corresponding hit in the crawl ratio department so steep decents and technical controllability in off road condidtions will suffer a bit. But such is life I guess.

As far as swapping out the whole drive line, well, anything's possible. The LR stuff is definitely a step down in reliabiliity from the G stuff (owned lots of LRs before going G), I can't speak for the Nissan stuff.

Let's just try and get him a nice set of MB gears to do the job. They will be dear though. Running over $1,000 USD per axle set right now. A ridiculous sum for a stupid pair of gears, in my opinion. I only wish we had a way to find out, "Oh, these are the same gears used in a Dana 44" or something, and be able to get common parts.[xx(]

Enough whining. Let me check if we can find some gear part numbers.

-Dave
 

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You could also check with Bill Moss or Ian Watson on the UK forums. I believe both have extensive experience with transplanting V8 engines in to G300s.
 

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pn's from the EPC, Can someone help with interchangeability?

That 3.73 axle ratio that Steve mentioned is listed as ring and pinion set 668 350 07 39. The EPC lists it as standard in a 290GD (463 model). I've also found part numbers for 4.4:1 and 4.1:1 ring and pinion sets, but always listed for 463 models. When I pull up the front and rear axles for that 290GD model, they both (axles) list the same ring and pinion set. When I pull up ring and pinion set numbers for 460 model trucks, the part numbers are always different for the front and rear axles, even for sets with the same number of teeth on the ring and pinion gears.

Maybe someone here can enlighten us about ring and pinion interchangeability from 460 to 463 front and rear axles.

Bottom line is there are ratios available, and we can find part numbers for you. Where I'm out of my element is in being able to tell you for sure that a given R&P part number will bolt into the axles you have at hand.

Hope we can help get this sorted.

-Dave G.
 

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RE: pn's from the EPC, Can someone help with interchangeability?

Dave G. is on the track. The 3,73´s are from automatic late model 290GD turbo. They are from the 461 series.

In theory the front and rear r&p should be the same in the 460 and 461 because the front differential is actually a rear one turned upside down. That way they get high pinion and the differential turning direction right for the gears.

Early 463 300GD´s had 4,111:1 gears (I have those in my car) and the later ones had 4,375:1. The 400CDI´s have 4,1 ratio.

The front axle of the 290GD´s is (according to my research) some blend between the 460 and 463. It is supposed to have the big wheel bearings of the 463 model and the differential of the 460.

If nobody has tried to fit these gears into a 460 it is a matter of measuring as set of them and compare. They might fit, could be a matter of different shim thickness or flange for the driveshaft etc.
 

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RE: pn's from the EPC, Can someone help with interchangeability?

Thanks Hinni!

If the front 460 diff/pumpkin is just an upside down rear, I wonder why they specify different part numbers for front and rear R&P sets on 460s. Seems with the upside down diff and counter-rotating front drive shaft the gear mating would be identical.

Curious.

-Dave
 

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RE: pn's from the EPC, Can someone help with interchangeability?

Hipine - 2/3/2005 9:35 AM
If the front 460 diff/pumpkin is just an upside down rear, I wonder why they specify different part numbers for front and rear R&P sets on 460s. Seems with the upside down diff and counter-rotating front drive shaft the gear mating would be identical.
I haven't had enough coffee yet this morning to wrap my brain fully around this concept, but could the reason for the different part numbers be that the R & P have teeth which are asymmetrical? If you put the rear gears in the front diff, now you're driving on the back side of the gear (that is, the sloping side rather than the vertical.)
 

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That's just it.....

In a 460 you wouldn't be driving on the back side because the drive shaft rotates the opposite direction at the front. Flip the pumpkin and reverse the DS direction and you drive on the same gear face. I always thought this whole setup was pretty clever for parts interchange, etc. That's why I can't figure out why the different part numbers. (driving on the back side is also not SO horrible....you do it every time you let off the gas and engine brake...but I wouldn't like to do it full time).

I mean, Steve S is clearly using the 290 gears in his truck. So if he has original 460 axles (maybe we can get him to confirm model #s from the axle tags if he isn't burried in a mudslide), then the same pn's work front and rear (there's only one pn for 3.73 r&p set), and the 290 was supposed to have a 460 pumpkin, as rumored by Hinni who I'm sure knows LOTS more about this stuff than I do.....

Fun fun.

Hey, where's mister fix-it in all this now?[:)]

-Dave
 

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Discussion Starter · #15 ·
I got to start on the vehicle today, it is a 460.3 300gd, it is tagged as being 9-44 which is 4.888 ratio, the rear diff is tagged -
l- 44-9 -4.9
typ HLO15S-1.8
fz 741502-7523977
var 1H5299

The front diff is tagged -
l- 44-9 - 4.9
typ ALO-1CS -1.3
fz 730300-7024197
var 1V4556

so i guess that limits my 460 chassis options, the idea of 461 chassis diff centers from a 290 sounds like a possibility. 3.73 gears would be the ratio i believe we require, at the moment the truck runs 3000 rpm at 50mph/80kph and a change to 3.73 will drop the revs to around 2100rpm - how do we get in contact with steve to find out?

then i suppose the question is where do we get second hand 461 3.73 ratio centers? any links or email addresses? if the centers are the same between 460 and 461 chassis' then possibly even part numbers would be a start.

thanks paul
 

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I'll get you the axle numbers from the 290GD when I get home this evening. I'll also shake some personal trees to see if I can get some reply from Steve S. He may not know who the gears were done though, since i think he bought his truck as is, and didnt' do the gear work. But he might have some paperwork or something.

In the mean time, you can take the part number for R&P from my previous post and at least check prices. Maybe you can find a parts supplier who'll let you return the gears if they don't fit, or might have another set of 461 gears that you could compare to once the set you have is out of the truck. Just some silly thoughts... [:(]

-Dave G.
 

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Discussion Starter · #17 ·
i spoke to the owner again last night and now he tells me he will more than likely go to 33inch tyres, form 265/70r15 so i may be better off finding ratio's around 4.1

we have a benz parts importer near here who has always been quite cheap for parts as he imports them himself, which really peevs the benz distributor here! so i may be lucky after i can price the part numbers.

again thanks for your work. [:D]
 
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