Author |
Message |
Roger Larsen Samba Member
Joined: July 16, 2004 Posts: 98 Location: Bloomfield Nm
|
Posted: Tue Oct 20, 2009 3:23 pm Post subject: 5 rib transmission compared to 6 rib |
|
|
Could anyone tell me the final gear ratio or a 5 rib transmission to the final gear ratio of the 76-79 6rib _________________ Roger Larsen |
|
Back to top |
|
|
VDubTech Samba Member
Joined: December 29, 2002 Posts: 9142 Location: Syracuse, NY
|
Posted: Tue Oct 20, 2009 3:40 pm Post subject: |
|
|
Have you tried searching? I know this has been gone over before. _________________ First Trip in the RustyBus:
http://www.thesamba.com/vw/forum/viewtopic.php?t=279077&highlight=
borninabus wrote: |
a measurement of your rod would be extremely useful. |
notchboy wrote: |
my dad wasnt a belittling cock when he tought me how to wrench on cars. |
EverettB wrote: |
One photo = good for reference.
10 photos = douchebaggery |
|
|
Back to top |
|
|
Roger Larsen Samba Member
Joined: July 16, 2004 Posts: 98 Location: Bloomfield Nm
|
Posted: Tue Oct 20, 2009 4:04 pm Post subject: |
|
|
Yes I find info on the ring and pinion ratio but is that the same as the total final ratio in 4rth gear. _________________ Roger Larsen |
|
Back to top |
|
|
Daverham Samba Member
Joined: August 27, 2009 Posts: 1397 Location: USA
|
|
Back to top |
|
|
Roger Larsen Samba Member
Joined: July 16, 2004 Posts: 98 Location: Bloomfield Nm
|
Posted: Tue Oct 20, 2009 4:27 pm Post subject: |
|
|
The reason I want to know is I currently have a 73 westy with a 2000cc typ e4 dual carb engine with a 6 rib and am very happy with the performance gas mileage and all. I had a 72 bus that had and 002 with a 1700cc that was the was very poor in performance and millage. I have a project in the works that I have the chance to buy a 5 rib. I plan on the same engine 2 liter with dual carbs. Is this a half way compromise or what can I expect for performance and mileage. I currently get a constant 19mpg and can run 70 mph on the flat all day long with my westy. _________________ Roger Larsen |
|
Back to top |
|
|
Roger Larsen Samba Member
Joined: July 16, 2004 Posts: 98 Location: Bloomfield Nm
|
Posted: Tue Oct 20, 2009 4:48 pm Post subject: |
|
|
Thank you very much Dave ham-Very helpfull _________________ Roger Larsen |
|
Back to top |
|
|
busdaddy Samba Member
Joined: February 12, 2004 Posts: 51060 Location: Surrey B.C. Canada, but thinking of Ukraine
|
Posted: Tue Oct 20, 2009 4:53 pm Post subject: |
|
|
After searching transmission AND rib AND ratio in baywindow and following a link I found this on type2.com
091 Transmission Data
by David Schwarze
--------------------------------------------------------------------------------
"All T4 trannies have the same ratios in 1st, 2nd, and 3rd gears. The differences appear in 4th gear and final drive ratios. From '68 through chassis 213 2068 548 (mid '73) the 4th gear ratio was 0.82. From there on to '79 the 4th gear was 0.89."
I've seen that published too, but my experience didn't bear it out. I have a late '73 bus with chassis number well after the one above, but my 4th gear was .82. Didn't find out till it was too late.
"The final drive ratio changed also, but at a different chassis #. From '68 through the end of the '73 model year (chassis 213 2300 001) the final drive was 5.375."
I think it's till the beginning of the '74 model year.
"Starting in 1974 chassis 214 2000 001) the final drive was changed to 4.867 through the end of the breadloaf series."
Not true - only '74 and '75 had the 4.867. 76-79 has 4.57 final drive (with the .89 4th gear).
"I happen now to own one of those oddball 0.89 4th gear, 5.375 final drive trannies."
I used to think that too. I'd be really suprised if you have one (I think they don't exist). Knowing the final drive, you could put it in gear, mark the shaft and prove me right or wrong by counting the number of turns on the input shaft vs. the output shafts.
"I also own a '78 tranny Tranny with the 0.82 4th and a 4.867 final drive, which allows 70+ cruising speeds, but quickly forces a drop in gears when you enter the mountains."
I think you have .89 4th and 4.57 final drive on that tranny.
"The advice I was seeking, since I am planning a cross country trip this June, is on which way to compromise. Should I seek the higher "flatland" speed across the midwest, or would the lower gearing of the late '73 tranny allow me to maintain speed in the mountains. The powerplant for this assemblage, BTW, is a '78 2L FI engine in a '73 body."
I still say keep the higher geared box. You'll do a lot more flat interstate than you will mountain passes. Here's a clip from a spreadsheet I made to help figure things out. The bastard transmission is a 78 case with the .88 4th gear and an oddball European ring and pinion (5.43/1) which combine for a serious stump puller. I used .88 for the 4th gear ratio in the later trans, but it may be .89. I've seen both in print and I haven't bothered to find out which it really is yet. Is it any wonder I don't trust anything I read about these tranny ratios anymore? The ideal trans is one I'm going to have built from my original '73 box with the .82 4th gear and the 4.86 ring and pinion from the '75 installed. I feel it will be a good compromise between freeway cruising speed and hill pulling in the lower gears.
Ring Final 4th gr 4th gear
and ratio ratio
Pinion Drive 0.88 0.82
----------------------------------------------
79 trans 32/7 4.57 4.02
75 trans 34/7 4.86 4.27
late 73 trans 43/8 5.38 4.41
bastard trans 38/7 5.43!! 4.78
ideal trans 34/7 4.86 3.98
And since that may have been a little confusing, here's another one that's a bit easier to understand. The first column is overall ratio in 4th gear, and the second column is how many RPMs you'll be turning at 60 mph with brand new 215/75R14 tires in back. Note that these tires are rather large. When I had 205/70's on the rear (which are comparable diameter to 195/75/14 btw) the RPMs were about 75-100 higher.
4th rpm@60mph
----------------------------------------------
79 trans 4.02 3326
75 trans 4.27 3534
late 73 trans 4.41 3644
bastard trans 4.78 3950
ideal trans 3.98 3293
Some of you are thinking that 3293 is a bit too low for the motor to be turning on the freeway, and you're probably right. It's okay though, because I'll be going back to smaller rear tires when I get this trans, which should put me at about 3375-3400 @ 60mph, which is exactly where I want to be (I'll normally be going 65ish anyway). One final thing to note is that putting bigger tires on the back of your bus isn't going to mess up the speedometer, because the speedometer is driven off of the front wheels.
The 091 trannies started in 76 in the US. At this time my best guess is that sometime in 74 they changed from 5.375 to 4.86, still in the 002 case. In 76 they started with the 4.57 and the 091 case. The 75 case was one year only, 002 number but with 091 style ribs on it.
This is one area where the Bentley appears to be a poor source of information. You really can't be sure what you've got until you open it up and look. You can just make an educated guess. _________________ Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
|
Back to top |
|
|
Roger Larsen Samba Member
Joined: July 16, 2004 Posts: 98 Location: Bloomfield Nm
|
Posted: Tue Oct 20, 2009 9:13 pm Post subject: |
|
|
Yes I have a double cab project I will be starting soon and when I travel I always seem to hit mountains. My Westy does great on flat land but when I hit the mountains we start to struggle. That is why I was considering maybe something besides the 091 but I do not want to go as low as the 002. Thanks for the help in doing my research. _________________ Roger Larsen |
|
Back to top |
|
|
gears Samba Member
Joined: October 28, 2002 Posts: 4391 Location: Tamarack, Bend, Kailua
|
Posted: Wed Oct 21, 2009 8:28 am Post subject: |
|
|
Yes, all the internet gear ratio lists that I've seen have some inaccuracies.
I think that all 4.86 (7:34) R&Ps will be found in "Pyramid" (5-rib) cases, which first came out in '74 and ran through '75. I could be wrong, but I believe that the earliest '74 Pyramid cases had the 5.42 (7:38) R&P, which was the replacement ratio for the weaker 5.38 (8:43).
Although all U.S. import '76-'79 091s (6-rib) had the 4.57 (7:32) R&Ps, there were many European model 091s that had either 4.86 or 5.42. There were even a few with lower R&P ratios than these (as with the Swiss ambulance).
It's nearly impossible to have totally reliable ratio lists. I don't think that even the factory was perfect in their record keeping. |
|
Back to top |
|
|
Roger Larsen Samba Member
Joined: July 16, 2004 Posts: 98 Location: Bloomfield Nm
|
Posted: Wed Oct 21, 2009 3:59 pm Post subject: |
|
|
I think my safest way to go will be to cough up the cash for a rebuilt 091. _________________ Roger Larsen |
|
Back to top |
|
|
patayres Samba Member
Joined: March 20, 2009 Posts: 991 Location: Bend, Orygun
|
Posted: Wed Oct 21, 2009 4:34 pm Post subject: |
|
|
You might call Ken @ German Transaxle and pick his brain. He serviced my 5 rib a few months ago and had very favorable reviews of it compared with the 6 rib. Bend is surrounded by hills and mountains, which he feels the 5 rib handles better.
http://www.german-transaxle.com/contact-us/ _________________ 1975 Westfalia Helsinki - 1800 EFI w/ Pertronix
1965 Singlecab - 1600dp
yuthi'so'coro |
|
Back to top |
|
|
Bluto Samba Member
Joined: January 30, 2004 Posts: 42 Location: Dallas, Tx
|
Posted: Sat Oct 24, 2009 6:07 pm Post subject: |
|
|
Roger,
The post above bearing my name IS very confusing and only parts of it were written by me. It's hard to make sense of it.
The answer to your original question is that the 091 has a 4.02 ratio and the 5-rib has 4.27. Both trannies have the same 4th gear (0.889), the only difference is that the 091 has a 32-tooth ring gear and the 5-rib has 34 teeth. If you go with the 5-rib you will reduce your speed by approximately 4mph at the same highway speed. Put another way, going with the 5-rib will raise your RPM by about 200 at 60mph.
-David _________________ Damn it feels good to be a gaaangsta |
|
Back to top |
|
|
Bluto Samba Member
Joined: January 30, 2004 Posts: 42 Location: Dallas, Tx
|
Posted: Sat Oct 24, 2009 6:23 pm Post subject: |
|
|
Roger Larsen wrote: |
Yes I have a double cab project I will be starting soon and when I travel I always seem to hit mountains. My Westy does great on flat land but when I hit the mountains we start to struggle. That is why I was considering maybe something besides the 091 but I do not want to go as low as the 002. Thanks for the help in doing my research. |
I also wanted to comment on this particular statement. There is almost no difference in the overall ratio in 4th gear between the 002 and the 5-rib. Only about 1mph difference at 60mph. This is due to the fact that the 002 has a taller 4th and shorter R&P while the 5-rib has a shorter 4th and taller R&P. So if the 002 is too low on the highway for you, the 5-rib will likely also be too low.
No free lunch unfortunately, you are going to have to either choose to be better on the flats or better on the hills, or increase the power output of your engine. Personally I would gear the bus for where you spend the majority of your time. Is it flat highway or hills? Which makes you angrier, downshifting on hills or having your speed limited on the flats? Oh, and remember that even with the 5-rib you will still probably be downshifting on bigger hills.
-David _________________ Damn it feels good to be a gaaangsta |
|
Back to top |
|
|
BabyJ Samba Member
Joined: April 24, 2015 Posts: 4 Location: Kentucky
|
Posted: Tue Apr 28, 2015 1:11 pm Post subject: |
|
|
Ran across this form and I have to ask.. I got a 2276 stroker cranks no more than 6000rpm which is the top power range of the cam... I got a 5
Rib stock gearing and running 31s what is the top speed of this thing per gear in mph? Not a major math fanatic but curious of the top speed of the transmission in 4th gear and each gear actually cause it's
Gonna be used 50/50 highway/woods can someone please calculate the mph in each gear for me? |
|
Back to top |
|
|
|