Is the 5-speed used in campers/vans like a W123 4-speed with an extra-low first? - PeachParts Mercedes-Benz Forum

Mölyapina · #1 02-13-2013, 09:00 AM

Quote:

Originally Posted by DeliveryValve

A 20 year old ford would still shift better. These 711 trans are noisy but are built like a tank to handle heavy duty usage. The gears are not shaped like a passenger car trans gears, so shifting is clunky and requires double clutching when down shifting. I just think it wouldn't feel right in a car... Bus yes... Car no...

So, I'm not opposed to double-clutching, but what is difference in the transmission? Why do I have a synchronized upshift but an unsynchronized downshift?

Quote:

Originally Posted by Stretch

Now I'm sorry to fly in the face of popular belief but I've always been pretty impressed by the car-like qualities of the TNs - compare their driving qualities with a manual gear box of the same era and I reckon they are about the same...

...I mean if you install a gear box that was designed in the 1970s you'll end up with that 1970s feel - there's no escaping it!

I actually prefer the shifting qualities of the older on the floor gear boxes than the more modern Sprinter linkages that usually spring from the dashboard tend to be really notchy and vague on the rentals that I end up having to endure.

What would you say are the differences in feel from, say, a 2004 Corolla? The Corolla doesn't feel very "vague" or "notchy", it just feels average.

Quote:

Originally Posted by t walgamuth

I would want to get measurements from the bell housing area, it may be a lot larger than the car bells. The adapter that bolts to the back of the motor may be larger in the truck/van. Also the shifter area on the van tranny looks pretty bulky to fit inside a car body.

This thing is a 207D engine/transmission, freshly lifted out of the truck.

Quote:

Originally Posted by vstech

IDK, those pics seem to show the truck bell is the same, and the shifter is just attached to the tail piece, it should easily be removed to use a car shifter...

That's what I was thinking -- just play with a 240D shifter and keep the knob from this one.

Mölyapina · #2 02-13-2013, 09:16 AM

...so is the TN transmission constant-mesh or sliding-gear?

Also, someone I contacted via PM raised the issue that the TN transmission was not built to handle the torque coming out of an 617.952, and would suffer premature death if mated to one. Does that sound right? I though that I remembered some camper owners upgrading to 617.952s with no reported problems. Does anyone have any thoughts one way or the other on that?

t walgamuth · #3 02-13-2013, 09:54 AM

Quote:

Originally Posted by Jooseppi Luna

...so is the TN transmission constant-mesh or sliding-gear?

Also, someone I contacted via PM raised the issue that the TN transmission was not built to handle the torque coming out of an 617.952, and would suffer premature death if mated to one. Does that sound right? I though that I remembered some camper owners upgrading to 617.952s with no reported problems. Does anyone have any thoughts one way or the other on that?

That sounds unlikely. The van/truck tranny should be a lot stronger than a car tranny.

Mölyapina · #4 02-13-2013, 09:56 AM

Quote:

Originally Posted by t walgamuth

That sounds unlikely. The van/truck tranny should be a lot stronger than a car tranny.

That's what I thought, too...

t walgamuth · #5 02-13-2013, 09:56 AM

Quote:

Originally Posted by Jooseppi Luna

So, I'm not opposed to double-clutching, but what is difference in the transmission? Why do I have a synchronized upshift but an unsynchronized downshift?

What would you say are the differences in feel from, say, a 2004 Corolla? The Corolla doesn't feel very "vague" or "notchy", it just feels average.

This thing is a 207D engine/transmission, freshly lifted out of the truck.

That's what I was thinking -- just play with a 240D shifter and keep the knob from this one.

This transmission looks longer than the four cylinder engine attached. The car four speed is nowhere that long, imho.

Really though, with the potential for distortion by cameras I'd want to see a picture of the truck and car tranny side by side.

Stretch · #6 02-13-2013, 12:45 PM

Quote:

Originally Posted by Jooseppi Luna

...

What would you say are the differences in feel from, say, a 2004 Corolla? The Corolla doesn't feel very "vague" or "notchy", it just feels average.

...

I've never driven a Corolla of that vintage so I can't say for sure but I get the impression that most modern Japanese vehicles of that ilk are dead boring but dead reliable. I'd expect that you'd hardly notice the shifting qualities of a Corolla - whereas for the gear boxes that you are considering I think you would!

I don't think that you are going to get a gear change - as in the actual feeling of the shift coupled with a smooth transition of power from the engine and an appropriate feeling of acceleration or deceleration of the vehicle like you get in your Corolla when you make the sort of DIY solution that you are suggesting.

Usually these types of solution are OK / great / excellent to the person who did it because they "did it" - only they are likely not to be critical about it - only they are happy to double de-clutch or ease off on the accelerator "when it does that" etc. Now there's nothing wrong with this kind of DIY modification - Renault do it all the time - but then they sell stuff to people who will put up with their **** because it is discounted and they get the feeling that they've had a good deal...

...sorry for the French car rant (!) - Basically be realistic with what you can achieve. Do some sums to see how you think the engine will cope in all gears not just the top end calculation.

Mölyapina · #7 02-13-2013, 01:31 PM

Quote:

Originally Posted by Stretch

I've never driven a Corolla of that vintage so I can't say for sure but I get the impression that most modern Japanese vehicles of that ilk are dead boring but dead reliable. I'd expect that you'd hardly notice the shifting qualities of a Corolla [You got it! That's what I was trying to communicate!] - whereas for the gear boxes that you are considering I think you would! [That's okay with me -- I like "feeling" something, which is probably why my favorite part of driving is working the clutch and double-clutching into first...]

I don't think that you are going to get a gear change - as in the actual feeling of the shift coupled with a smooth transition of power from the engine and an appropriate feeling of acceleration or deceleration of the vehicle like you get in your Corolla when you make the sort of DIY solution that you are suggesting.

[...so are you saying that the double-clutching in my Corolla is not the same as double-clutching a TN? I expect that. The Corolla is too lax on me when my double-clutch is slightly off.]

Usually these types of solution are OK / great / excellent to the person who did it because they "did it" - only they are likely not to be critical about it - only they are happy to double de-clutch or ease off on the accelerator "when it does that" etc. Now there's nothing wrong with this kind of DIY modification - Renault do it all the time - but then they sell stuff to people who will put up with their **** because it is discounted and they get the feeling that they've had a good deal...

[If you love French cars so much, why do you have a German one?

]

...sorry for the French car rant (!) - Basically be realistic with what you can achieve. Do some sums to see how you think the engine will cope in all gears not just the top end calculation.

[...working on that right now.]

Thanks for your reply! Sorry if I had trouble grasping parts of your post -- my concussion gets at me occasionally.

DeliveryValve · #8 02-13-2013, 01:36 PM

Quote:

Originally Posted by Jooseppi Luna

So, I'm not opposed to double-clutching, but what is difference in the transmission? Why do I have a synchronized upshift but an unsynchronized downshift?

.

My understanding the gears are straight cut as opposed to helical. Yet more durable, they can be noisy and downshifting a bit rough. Double-clutching on a downshift would bring the RPM on par with the gear's speed at that moment. Upshifting is not so dramatic in terms of matching the speed.

t walgamuth · #9 02-13-2013, 02:40 PM

perhaps they are straight cut on first and reverse.

Mölyapina · #10 02-13-2013, 03:02 PM

Quote:

Originally Posted by t walgamuth

perhaps they are straight cut on first and reverse.

Well, then it would only be loud in the city...

Mölyapina · #11 02-13-2013, 03:11 PM

So it looks like a camper transmission with the 4.7:1 first gear would hit 2000 RPM at 12 MPH in first with the 2.47:1, while hitting 2000 RPM in fifth at 57 MPH (ASSUMING that 5th in the campers is 1:1). This sounds like the ideal fit! If it isn't too noisy (or if it can be silenced with sound insulation on one or both sides of the tunnel), and fits, I may start looking for a camper transmission

Oh! Would a W123 clutch fit? It would be a pain to look for a camper clutch.

DeliveryValve · #12 02-13-2013, 04:42 PM

Quote:

Originally Posted by Jooseppi Luna

So it looks like a camper transmission with the 4.7:1 first gear would hit 2000 RPM at 12 MPH in first with the 2.47:1, while hitting 2000 RPM in fifth at 57 MPH (ASSUMING that 5th in the campers is 1:1). This sounds like the ideal fit! If it isn't too noisy (or if it can be silenced with sound insulation on one or both sides of the tunnel), and fits, I may start looking for a camper transmission

Oh! Would a W123 clutch fit? It would be a pain to look for a camper clutch.

I got a 2.47 LSD carrier that you can buy from me and install in the proper case.

I think it's a 10 spline input shaft. You should be fine with a w123 616/617 clutch.

Mölyapina · #13 02-14-2013, 06:12 AM

Quote:

Originally Posted by Jooseppi Luna

So it looks like a camper transmission with the 4.7:1 first gear would hit 2000 RPM at 12 MPH in first with the 2.47:1, while hitting 2000 RPM in fifth at 57 MPH (ASSUMING that 5th in the campers is 1:1). This sounds like the ideal fit! If it isn't too noisy (or if it can be silenced with sound insulation on one or both sides of the tunnel), and fits, I may start looking for a camper transmission

Oh! Would a W123 clutch fit? It would be a pain to look for a camper clutch.

...and the 6.14:1 with the 2.24:1 would hit 10 MPH in first at 2000 RPM while hitting 63.75 MPH in the presumed 1:1 5th gear at 2000 RPM.

Stretch · #14 02-14-2013, 10:42 AM

Quote:

Originally Posted by Jooseppi Luna

...and the 6.14:1 with the 2.24:1 would hit 10 MPH in first at 2000 RPM while hitting 63.75 MPH in the presumed 1:1 5th gear at 2000 RPM.

Hey Jooseppi have you done the calculations for the W123 standard gear boxes and final drive differential ratios and compared them with your calculations?

Even 10 mph at 2000rpm seems a tad quick compared with my calculations for the standard set up - I don't reckon you'll be doing many hill starts (unless your nose is pointing down!) with that configuration.

Have you also been looking at the downshift characteristics? For example even if you manage 2000 rpm in top gear with out the engine stalling and you bump it down a cog - do you over rev the engine? (Probably not but is your proposed gearing useable - do you get what I'm saying?)

{I'm trying to find some estimations of power required to keep the whole thing rolling for you}

Mölyapina · #15 02-13-2013, 03:01 PM

Quote:

Originally Posted by DeliveryValve

My understanding the gears are straight cut as opposed to helical. Yet more durable, they can be noisy and downshifting a bit rough. Double-clutching on a downshift would bring the RPM on par with the gear's speed at that moment. Upshifting is not so dramatic in terms of matching the speed.

Aaah, straight-cut! The reverse gear in our Corolla is straight-cut, and it's definitely louder than the forward gears. Darn. Did all the gears make the same noise, or are some of them helical-cut?