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Mon Aug 01, 2011 3:32 pm

in my 1.6td doka im thinking of swapping from a diesel 4 speed to a 5 speed gasser trans would this be beneficial to me?

Mon Aug 01, 2011 7:31 pm

take a look at the gearboxes page on the website http://northamericanhightops.com - you'll find a link to a PDF listing all of the 4 and 5 speed gearboxes made along with their gearing ratios. There is another link to a site with a super calculator function that allows you to input all of the ratios, tire size etc and then you can see the effect on final speed. Have fun poking around with it - everything is a tradeoff.
JC

Mon Aug 01, 2011 10:08 pm

Depending on the year of your diesel chassis,you'll end up swapping a bunch of parts :x

Tue Aug 02, 2011 2:46 am

its a 1990 im under the assumption i will have to change my linkage and shifter is this correct

Tue Aug 02, 2011 4:36 am

It depends on why you want to change from 4 speed to 5 speed.

If you think that you're going to end up with a higher top gear, then it's not down to 4 or 5 speed but is based on the final drive ratio.

The 5 speed vanagon gearbox is actually a 4 speed gearbox with an extra lower gear below the normal gears. The only thing you gain with the 5 speed is slightly closer ratio gears.

What you lose is an easy to select 1st gear and an easy to shift 1st to 2nd gear as 1st is on a Dogleg behind reverse. Not great for quick shifts.

If somebody offered me the option of a 4 speed or a 5 speed in a vanagon with the same final drive, I'd go for 4 speed every time.

The parts you'd need to change would include the front gearbox mount, gear shifter and shifter box (sits under the shifter up front).

The 5 speed is also more troublesome when things go wrong. When the pinion bearing wears (note I said 'when', not 'if'), 1st gear takes all the load of the gearbox and slowly kills itself and the pinion shaft. The 4 speed doesn't have these parts.. so it can't.

The last thing is that with 1st gear being housing outside of the main casing, it's not as strong as the gears inside the main housing. This effectively puts the 4 speed as a stronger gearbox as the torque put through the component in the gearbox is at it's maximum in the lowest gear... i.e. 1st gear.

MG

Tue Aug 02, 2011 5:24 am

I of course am not in the same leaque as you guys but I've been driving 5 spd exclusively since they came out. I love them and am sure I could adapt to a 6th. Scooby really really really wants a 5th gear at the top end, just to take some load off the engine. It is very evident that she is a good candidate to the 5th but I don't think it will happen. I understand that when Vanagons were originally designed and built that 4 spd was the one up from the 3 gear, wouldn't it be great if you could put a Jetta 5 spd into a Vanagon just like you can put their engine (TD) in. Yep Scooby needs that 5th for sure.

Tue Aug 02, 2011 7:17 am

i know that the diesel 5 speeds 1st gear is a granny gear but from what i have read elsewhere a gasser 5th gear is like an highway gear in the european models

does my statement hold any truth

Tue Aug 02, 2011 8:17 am

sub-hatchtim wrote: i know that the diesel 5 speeds 1st gear is a granny gear but from what i have read elsewhere a gasser 5th gear is like an highway gear in the european models

does my statement hold any truth

Nope. As mentioned above, the Euro 5 speed has a very similar overall ratio in top gear as the DU or ABD 4 speeds.

The AAP and AAR 5 speeds combined the lower 4.57 final drive ratio with the .816 5th gear set while the 7D and 8D boxes used a .77 5th with the usual 4.86 ring & pinion. These are the only factory transaxles with a 'highway' gear but these days there are guys like Darryl Christensen and Gary Zink mixing and matching ratios to make a more useful set of gears for North American driving in the 21st century.

Jeff Schwaia has a very complete list of T3/Vanagon transaxles at: http://vanagonparts.com/home.html > Technical Information > ID & Gear Ratios

Tue Aug 02, 2011 9:07 am

DAIZEE wrote: . . . wants a 5th gear at the top end, just to take some load off the engine . . .

using a "higher" gear puts more load on the engine, as the mechanical advantage provided by the transmission is less than when you use a "lower" gear. The engine makes much more power at higher RPMs.

Ever ride a ten-speed bike? Think about how hard it is to climb a hill in the big gears (big sprocket at the front), compared to effortlessly spinning with the tiny sprocket on the cranks.

Tue Aug 02, 2011 9:50 am

240Gordy wrote: DAIZEE wrote: . . . wants a 5th gear at the top end, just to take some load off the engine . . .

using a "higher" gear puts more load on the engine, as the mechanical advantage provided by the transmission is less than when you use a "lower" gear.
Yep. Load is the wrong word, here. The problem with DAIZEE's AAZ (and mine) is an awful lot of noise above about 3400 RPM. The narrow useful RPM band of the IDI diesels practically begs for a couple more gears in the transaxle. You can make it a bit better by increasing the overall gearing (using higher final drive or larger tires) making each gear cover a larger MPH/KPH range, and even more with the use of custom gear ratios for each gear. Perfection, however, just isn't going to happen in a diesel Vanagon. It wants you to slow down and enjoy the ride.

Tue Aug 02, 2011 9:53 am

Yes of course I was speaking of cruising flat 100 to 120 kmph. I know to gear down on hills etc... Been driving 4 & 5 speed for more than 5- plus years :wink: I drive by the sound of my engine combined with what i see on the tach. My little Tercel goes like crazy and loves 5th gear. Drops the tach several hundreds. I was just saying Scooby with the new TD motor is hollering for 5th. Just an experienced observation, I'm not a professor. :)

Tue Aug 02, 2011 9:54 am

sorry computer hung up :oops:

Tue Aug 02, 2011 9:55 am

ditto :oops: :)

Tue Aug 02, 2011 9:58 am

:oops: :roll:

Tue Aug 02, 2011 10:06 am

[-X sooooo sorry, I had to do a reboot. Computer must be a dumb blonde!

Tue Aug 02, 2011 10:22 am

1990 is fine.

take the whole linkage and the tranny front mount that is bolted to the nose of the tranny.

Regular passenger TD 5 speed like AAS are 30 km/H for 1000rpm in 5th with original wheels.
The higher you can get from stock gasser 2.1L DJ like mentionned above (AAP and similar) is 32 km/H in 5th at 1000rpm.

SO you can expect 32x4.5=144 km/h at 4500 rpm therorically with that kind of tranny.

If you want better,then replace ring and pinion and or gears.€€€ :wink:

Tue Aug 02, 2011 11:22 am

I have the ASS diesel 5spd in my '85 gasser and am quite pleased with it. While the true 5spd shifter would be nice, the 4spd can be modified to work fine. For now, first is a little short. However, the current 4th is perfect for hills. I no longer have to choose between lugging in 4th or high reving in 3rd. The 5spd fourth gear is right in the middle between the original 4spd 3rd and 4th. I can climb the 7% grade at 50+mph and keep a reasonable rpm. I am currently on stock tires.

Unless you plan to upgrade from the 1.6td, I would avoid the AAP and its 4.57 r&p. See if you can find an ASS. The ASS was used in front of the euro 1.6td in '90 and '91.

Good luck

Hans

Tue Aug 02, 2011 11:42 am

hdenter wrote: See if you can find an ASS.
Yeah Tim! See if you can find an ASS! :lol:
Yer DoKa is gonna need it!

BTW- Send me a proper e-mail addy, and I can send you an 'official' gear ratio guide from VW.

Tue Aug 02, 2011 12:58 pm

Domo wrote: hdenter wrote: See if you can find an ASS.
Yeah Tim! See if you can find an ASS! :lol:
Yer DoKa is gonna need it!

BTW- Send me a proper e-mail addy, and I can send you an 'official' gear ratio guide from VW.

Please send it to: [email protected]

Tue Aug 02, 2011 1:44 pm

at 3400 rpm with 215 70 15 tires overall diameter 26.85" you would expect : 1. with the standard gasser gearing (4.83R&P, .823 4th, 1.26 3rd) in 4th 68.35mph, in 3rd 44.6mph
2. with (eg) the 5 sp diesel gearbox for the 1.6TD engine (3H code) with a 4.83 R&P , .816 5th and 1.023 4th at 3400 rpm 5th gear gives 69mph, 4th is 55mph
Its not the top speed that is significantly different between the 4 and 5 speeds, it is the option of a gear between 3rd and final.