Rebuilding transaxle with Samba help! 091/1 (fun starts pg 4)

[erste]

[old_man]

erste,

Thanks for the input and the link to the calculator. I've been looking for a good one and that is certainly a good one. It seems if I change my 4th from .78 to .70 it would put me in a decent spot.

[erste]

Good luck! You went from 0 to 100 in a post or two.

AndyBees posted about his gearing and peak torque in this thread on tdiclub. Might be helpful:
http://forums.tdiclub.com/showthread.php?t=279543&page=18

This series on youtube is worth a watch as you're looking into the swap:
https://www.youtube.com/watch?v=PmqdYNkykXE

There's a more recent thread in here that I'm looking for about driving-style with the TDI. I'll post back when I find it because the discussion was interesting.

[AndyBees]

I read thru most of this thread up to this point........quite interesting..

OP, I rebuilt the 091 (from a 1980 air-cool) that I installed in an 84 Vanagon for my ALH TDI build project (rolled out of my little garage, August, 2012). It is the DK code with 4.57 Ring & Pinion. It now has over 82k miles on it. As some of you may know, I've pulled a popup camper to Alaska and back twice with no tranny issues.

I've rebuilt several 002 transmissions (1968-1975 Transporters). The 091 is quite similar (1976-1983). Both, require the use of a jig to set the gear shifting forks. As I understand, the 002 and 091s are more difficult to assemble than the 091/1 and 094 (Syncro). It is my understanding that the 091/1 doesn't require the use of a jig......... not been there yet.

When I rebuilt the 091 for the TDI project, I had never opened a VW manual trans previously...... had no specialty tools either. Anyway, I replaced all syncros, all bearings except the pinion, upgraded the 3rd & 4th hub/slider and gears as well as replaced shifting forks and reverse gear. After the rebuild, the tranny has always had a whine in 3rd and 4th when letting up on the accelerator (coasting in gear). I just assume that the whine is from those thick cut aftermarket gears..

I'm waiting on the availability of a new 4.13 Ring & Pinion from Weddle. I plan to rebuild another DK to include the 4.13 with the same upgrades for 3rd and 4th gears. If my calculations are correct, the 4:13 R&P should result in a substantial drop in RPMs. The 4.57 R&P in my current DK air-cool tranny with .77 4th and 215/75/15 tires result in about 3050 RPMs at 70 mph.

As for clutches......... well, unlike Mark, the OE clutch/pressure plate for the Diesel tranny would slip in my set-up and this was before a Stage 1 Malone Tune. So, I installed a SMF and later installed the input shaft to accept the TDI clutch disc. I ran this for about 20k to 30k miles. Then, I installed a SACH Dual Mass Flywheel/Clutch assembly.......... never happier! It is extremely quiet and smooth. Yes, the inside of the bell housing required clearancing in two or three spots....... no big deal. The OE Vanagon clutch disc can be used in place of the disc that comes with a DMF package (thus, no need for the upgraded TDI style input shaft).

I got all of my parts from Weddle. Their web site is easy to use.

Following this interesting Thread...
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'84 Vanagon Tin-top, ALH TDI. 1989 Tin-top
1983 Air-cool, 225k miles, 180k miles mine. Seven trips to Alaska from 1986 thru 2003.

[T3messie]

There already is a noticeable gap between 3 and 4 in the ABH, so think about making the third longer too.

[old_man]

[tjet]

This rebuilding CD is a good investment

http://www.longenterprises.com/Rebuilders_course_photo_gallery/index.htm

[old_man]

[old_man]

[MarkWard]

In my setup, the ring and pinion makes all the gears taller. This allowed me to run a slightly taller 4th. .77 You don't even notice the rpm drop between the stock 3rd and 4th. The stock 3rd gets used all the time when not on the highway. It seems perfect for mountains as well. Your results may vary.
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[?Waldo?]

I would not exclude the possibility of swapping the R+P. Having very short 1st and 2nd when taller 3rd and 4th are desired seems counterproductive. Consider 4.57 or 4.14 with the gears as they currently are.

[old_man]

[?Waldo?]

Have you looked here:

https://www.vw-t3-bus-shop.de/en/pinion-crown-gear-for-vw-t3-bus

FWIW, the shaft of the 5-speed R+P can be shortened and used as a 4-speed. Even after shipping they are likely less expensive than the North American big hitters. If you register for a free account and log in all the prices go down by ~15%. That's also a good place to get the Vanagon TDI input shaft so you can run a complete TDI clutch kit.

[old_man]

Thanks Waldo, I just found them.

Edit: I found some at brickwerks that are even cheaper. So say I can cut a 5 into a 4? That is nice. What would you say the difficulty of installing a new one in would be without a way to measure depth is? I don't know if 4.57 or 4.14 is better. 4.57 is cheaper.

[erste]

From my experience the 4.57 (stock 1st and 2nd DK gearing) was acceptable, but you'd be shifting out of first before crossing the intersection. With the 4.14 first gear is more usable, shift point seems more like a 'normal' vehicle.

[AndyBees]

OP, this graph pretty much mirrors the real world with the 4.57 R&P in my DK tranny with 1.14 3rd and .77 4th. The representation is with 215/75/15 tires.

The bottom plot is for 1st gear and on up is 2nd, 3rd and 4th gears.

Notice there is about a 1500 RPM drop from 1st to 2nd...... a 1400 RPM drop from 2nd to 3rd, and then a 1100 RPM drop from 3rd to 4th. This has worked just fine. However, I did this graph before I put the vehicle on the road. So, my real world shift points are very near 3000 RPMs and I cruise at 3050 RPMs in 4th which is 70 MPH. And, running the RPMs up higher in each gear puts the TDI engine close to peak torque (about 1900 RPM) when shifted to the next gear.

The necessary early shift from 1st to 2nd is not a problem. Sooner or later you have to shift is how I see it.

A 4.14 R&P will look about the same on the graph. Of course, I suspect the most noticeable difference would be when pulling out in 1st and then the lower RPMs necessary to maintain a certain speed in 4th gear.

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'84 Vanagon Tin-top, ALH TDI. 1989 Tin-top
1983 Air-cool, 225k miles, 180k miles mine. Seven trips to Alaska from 1986 thru 2003.

[old_man]

AndyBees,

I would have slightly smaller tires than you coming in at around 27. Currently I have 1.23 3rd and a .78 4th. Maybe the 4.57 is right for me then and leave all else the same. I think it would look very similar to your set up except 3rd.

Curious, did you swap out the pinion yourself?

[AndyBees]

[old_man]

Seems like I'm getting a growing consensus that going to a 4.57 would be the best solution. If anyone in the future reads this please note that I have a bit of an unusual stock transmission compared to other North American models.

I'm currently building a shopping cart at Brickwerks, much like Waldo said Euro prices seem to be cheaper that Weddle. Sometimes considerably. I'm hoping it's not a quality issue. Seeing as I am going to have to exchange currency and pay outrageous UPS fees either way, I might as well go with the cheaper option. I think some stuff I still need from Weddle. Back to the reason I started this thread, I'm still trying to figure out all the bearings I am going to need. Perhaps it would be wisest if I tear into my transmission tomorrow.

[T3messie]