Mercedes-Benz Forum banner

1 - 13 of 13 Posts

·
Registered
'86 W123 200, OM617 non-turbo, bastard 5-speed; '95 W202 C250 Diesel, OM605 non-turbo, 5-spd man
Joined
·
4,269 Posts
Discussion Starter #1
What is the difference between the petrol and diesel model gearboxes' input shafts? Number of teeth, helix angles, other dimensions?

Thx
 

·
Premium Member
About a dozen 1988, 1989, 1990, and 1991 sedans, wagons, 4Matics and 1 coupe
Joined
·
5,466 Posts
I think it's just the gear ratios which give shift points that are matched to the diesel's power curve. Someone on this forum has posted about installing a diesel transmission in a gas car and it works. I think the recipient car was even a coupe!
 

·
Registered
'86 W123 200, OM617 non-turbo, bastard 5-speed; '95 W202 C250 Diesel, OM605 non-turbo, 5-spd man
Joined
·
4,269 Posts
Discussion Starter #3
On most vehicle with petrol and diesel engines sharing gearboxes, the diesel 'boxes have coarser splines on the input shaft than the diesel to cope with the increased vibration levels. Just so for the W123 series. I know from experience on Toyota Land Cruisers that the petrol input shaft sounds like it's about to fall apart if fitted to a diesel engine, but the converse naturally doesn't happen.

But I need to know if that is the only difference. On some of the models there is a difference in length, and/or a differenence in the number of teeth on the input shaft gear. Are there similar things to look out for on series W124/W201 petrol vs. diesel 'boxes?

Thank you Mercedes for not standardizing your design across the entire model range...
 

·
Registered
Depends on the week
Joined
·
3,726 Posts
I think it's just the gear ratios which give shift points that are matched to the diesel's power curve. Someone on this forum has posted about installing a diesel transmission in a gas car and it works. I think the recipient car was even a coupe!
that was me :D

there really is no difference between the transmissions, they're just tuned to each particular car's power band.
if you were to use the diesel transmission in a gas car, use the gas torque converter with the diesel trans or vise versa if using the gas trans in the diesel. the stall speeds on the converters are different and will create some awkward driving if the torque converters aren't matched to the engines, ask me how i know (was quickly remedied with the switching of the torque converters)..


i did eventually get fed up driving an autotragic and followed suit with a shift 5 swap. everything is just peachy aside from me finding a suitable final drive. :)
 

·
Registered
Depends on the week
Joined
·
3,726 Posts
But I need to know if that is the only difference. On some of the models there is a difference in length, and/or a differenence in the number of teeth on the input shaft gear. Are there similar things to look out for on series W124/W201 petrol vs. diesel 'boxes?

Thank you Mercedes for not standardizing your design across the entire model range...
Although the transmission found on the m102 will bolt up and move your car, don't use it . it's mechanics are different then the m103 transmissions.

stick with transmisions from the inline 6's
 

·
Registered
'86 W123 200, OM617 non-turbo, bastard 5-speed; '95 W202 C250 Diesel, OM605 non-turbo, 5-spd man
Joined
·
4,269 Posts
Discussion Starter #7
Although the transmission found on the m102 will bolt up and move your car, don't use it . it's mechanics are different then the m103 transmissions.

stick with transmisions from the inline 6's
I'm interested in knowing if there is a difference in the input shaft from, say, a 717 411 gearbox mated to a OM602 and an M102.

On the 123 series, the 4 spd manual 716 005 mated to the inline 4 cyl M115 differed to the 716 005 mated to OM616 in as far as the OM616 diesel's input shaft splines were coarser than that of M115. The input shaft from 716 211 mated to M102 was also shorter than that of 716 005 mated to M115, even though the mechanicals are mostly identical.

Some detail drawings and dimensions of the input shafts would be nice - a picture paints a thousand words, after all. Sadly, Mercedes doesn't want to provide me with them.
 

·
W124 Moderator
86 190E 2.3L 16V, 2 95 320TE's, 02 S500
Joined
·
12,744 Posts
PlaneCrazy

Just curious... What project are you wanting to execute with this line of questions?

Jayare
 

·
Registered
Depends on the week
Joined
·
3,726 Posts
I'd love to know more about this. Was there a build thread?
i have a build thread of the whole work in progress car with a link to a whole pdf file containing part numbers and some description/pictures. the pdf file is i think the 5th or so post from the 1st: View topic - Allen's flatline 300CE build | THE Mercedes-Benz & AMG Forum for and by the Enthusiasts | MyMBonline.com

I'm interested in knowing if there is a difference in the input shaft from, say, a 717 411 gearbox mated to a OM602 and an M102.


Some detail drawings and dimensions of the input shafts would be nice - a picture paints a thousand words, after all. Sadly, Mercedes doesn't want to provide me with them.
the om602 is a completely redesigned engine from the om617, thusly you have to step completely away from the w123 mindset with the w124. everything is different. mercedes was in a time period where the cars were all very much alike and all utilized very similar engines for them to have variances between these engines for the sake of being in different cars, would make absolutely no sense economically.

there is no difference in the input shafts. what matters is what kind of flywheel you will be using and the length of the input shaft is what you're going to have to watch out for. i think i've described the why's and how's of that in my shift 5 DIY pdf.

for time, i'll mention it again and we'll use the w201 as an example. same basic engines as the w124, similar body. a lot of parts from a w201 are transferable to the w124 and vise versa. the 717.411, is exactly the same between the diesel and gas w201.

now, the only thing that you should pay attention to is which flywheel goes with which transmission.. prior to 9/89 all mercedes stick shifts had a single mass flywheel which utilized a long input shaft. after that date, mercedes moved to a dual mass flywheel and a short input shaft on the transmission had to be used because of it. the dual mass set up was used because the dual mass set up removes a lot of the drivetrain vibration present with a single mass set up.

whatever you know about a w123 with input shafts and what not, do not apply to the later models. the input shafts are all the same 26 spline whether they are long or short. one is not courser than another because it's a diesel. hopefully, the above will have answered your questions in regards to what you should keep your eyes on.
 

·
Registered
'86 W123 200, OM617 non-turbo, bastard 5-speed; '95 W202 C250 Diesel, OM605 non-turbo, 5-spd man
Joined
·
4,269 Posts
Discussion Starter #11 (Edited)
@ bsmuwk:

thanks, I pretty much figured that, but it doesn't hurt to check. I noticed that some models have two or even three different sets of ratios for the same engine on the W124 models. Manual W124s are hard to come by in South Africa, so I would just need to dispel my doubts about the stuff I'm buying. Also, the dual mass flywheels didn't make it into SA until the W203 series, probably due to the relative unpopularity of manual Merc's (why, oh why...) and they are notoriously "fragile" and expensive. So it's just me making sure that what I'm given is correct, not just saleman's banter.

Don't be mistaken - I get paid to be paranoid...

@Jayare:

It's called "parts hunting..." for a 300D (OM603 12 valve)
 

·
Registered
Depends on the week
Joined
·
3,726 Posts
so what trans did you use for your own swap? my car has a 3.2L M104 and I've considered doing this for fun.
i ultimately settled on the 717.411 for it's overdrive, but i have a rebuilt cosworth getrag in storage to put in for track time. both transmission's use a single mass flywheel, so it's just a matter of swapping the shifters and swapping the transmissions....just peachy..:)
with the overdrive in the 717.411 instead of turning 3k rpm at 65 mph i'm turning 3k rpm at around 83-85mph with a 3.06 final drive. :D i'm dissappointed with off the line performance with my final drive so i'm looking to replace with a 3.27 final drive with LSD.

i'm afraid to calculate my fuel mileage because i found the car just too damn exciting to drive. it's a totally different animal. 0-60 comes and goes and from there it just climbs and climbs with no end. just imagine the top speed of a w124 with an automatic transmission........but with another gear to go....just giddy!


@ bsmuwk:

thanks, I pretty much figured that, but it doesn't hurt to check. I noticed that some models have two or even three different sets of ratios for the same engine on the W124 models. Manual W124s are hard to come by in South Africa, so I would just need to dispel my doubts about the stuff I'm buying. Also, the dual mass flywheels didn't make it into SA until the W203 series, probably due to the relative unpopularity of manual Merc's (why, oh why...) and they are notoriously "fragile" and expensive. So it's just me making sure that what I'm given is correct, not just saleman's banter.

Don't be mistaken - I get paid to be paranoid...

@Jayare:

It's called "parts hunting..." for a 300D (OM603 12 valve)
They have different sets of ratios in the transmissions for different final drives. the dual mass flywheels were standardized across all models after 9.89 whether they were popular or not... maybe SA is an oddball in that regard? dual masses are ridiculously unreliable, that's why i have the ever impossible to find single mass. :D
 

·
Registered
'86 W123 200, OM617 non-turbo, bastard 5-speed; '95 W202 C250 Diesel, OM605 non-turbo, 5-spd man
Joined
·
4,269 Posts
Discussion Starter #13 (Edited)
i ultimately settled on the 717.411 for it's overdrive, but i have a rebuilt cosworth getrag in storage to put in for track time. both transmission's use a single mass flywheel, so it's just a matter of swapping the shifters and swapping the transmissions....just peachy..:)
with the overdrive in the 717.411 instead of turning 3k rpm at 65 mph i'm turning 3k rpm at around 83-85mph with a 3.06 final drive. :D i'm dissappointed with off the line performance with my final drive so i'm looking to replace with a 3.27 final drive with LSD.

i'm afraid to calculate my fuel mileage because i found the car just too damn exciting to drive. it's a totally different animal. 0-60 comes and goes and from there it just climbs and climbs with no end. just imagine the top speed of a w124 with an automatic transmission........but with another gear to go....just giddy!




They have different sets of ratios in the transmissions for different final drives. the dual mass flywheels were standardized across all models after 9.89 whether they were popular or not... maybe SA is an oddball in that regard? dual masses are ridiculously unreliable, that's why i have the ever impossible to find single mass. :D
SA is not an oddball, it's just that maybe our high altitude and hot, dry weather is performance-sapping, so that a cheap solution to provide zesty-ish performance would be to not fit overdriven gearboxes (we always got the automatics with the new model releases), or maybe we're just the scrapyard of the world - what better way to profit from excess stock than sell it cheaply to the third world ("they'll never know the difference")...

Anyways, if you are all adament that the splines look the same on petrol and diesel models, I'll trust your judgement and accept that my replacement input shaft is, in fact, correct.:thumbsup:
 
1 - 13 of 13 Posts
Top