Upgrade 5 speed to 6 speed gearbox

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desertstorm
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Passat model: B5.5 130 TDI AWX
Location: Cannock

Upgrade 5 speed to 6 speed gearbox

Post by desertstorm » Thu Dec 27, 2012 10:36 pm

5 speed to 6 speed gearbox upgrade

Why would you want to upgrade from a 5 speed to 6 speed box.
The 6 speed box has better ratios ?. Well it does have an extra gear but depending on what you want in the way of extra performance or better high speed cruising would determine which box to fit.
1st , 2nd and 3rd are pretty much the same in all the boxes the differences start when you get to 4th gear.

From the 5 speed to 6 speed gearbox ratios post I made.

viewtopic.php?f=33&t=45467

FHN ......... FRK ......... DQS
1 13.011 .... 13.563……..13.563
2 7.494 ..... 7.320……….7.320
3 4.683 ..... 4.766………..4.766
4 3.110 ..... 3.617………..3.375
5 2.363 ..... 2.83…………2.583
6 ............ 2.325………….2.174

You can see 1st , 2nd and 3rd are all the same in the 6 speed boxes 4th 5th and 6th are different.

That gearing corresponds to the following speeds at 4700rpm.

FHN ......... FRK...... DQS
1 26.7 ...... 25.65…..25.65
2 46.4 ...... 47.5...….47.5
3 74.3 ...... 72.98…..72.98
4 111.9 ..... 96.2……103.1
5 147 ...... 123……...134.7
6 ............ 149.6…….160.0

And looking at the engine speed at 80mph on each gearbox in top gear the revs would be

FHN..............FRK.............DQS
2560 RPM ......2513 RPM......2350 RPM

FHN is the original gearbox in my 2002 5 speed 130TDI, FRK is one of the gearbox codes for the 130TDI sport and DQS is a 6 speed out of a 2.5 V6.

The 6 speed boxes have a 240mm clutch instead of the 228mm item fitted to the 5 speed box, so this makes it easier for cars that have been tuned as the 240mm clutch handles the torque and power better.
So what do you need to change from a 5 speed to a 6 speed gearbox?

Well most importantly the gearbox itself, after you have decided which one to go for, I fitted an ELN gearbox, this is the earlier 6 speed box built by Getrag and not affected by diff bearing issues that can affect later boxes such as the FRK.
Here's a picture of the original box

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And the replacement, you can see the home made plate for the transmission mounting.

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The driveshaft mountings are 130mm on the 130TDI on lower power engines or earlier ones they may be 100mm in which case you would also need driveshafts.

You will need to replace the complete gear selector mechanism as the selector rods are different between the gearboxes.

5 speed

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6 speed

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The starter motors are different as the flywheel diameter is different between the 228mm DMF and the 240mm DMF. The 6 speed starter motor is a lot longer than the 5 speed one and the support that goes from the turbo to the engine block won’t fit with the new 6 speed starter motor so had to be removed.

Image

I bought my gearbox from a forum member who broke his car. Thus I got the gearbox , starter motor, DMF, clutch plate and pressure plate in one go. Also on the car there was a 5.5mm spacer plate between the gearbox and engine. This appears to be fitted to all 6 speed gearboxes and not on the 5 speed gearbox. The part number is 01E103551B.

There are 2 locating dowels on the back of the engine and when the spacer is fitted these would no longer protrude beyond the spacer to locate the gearbox. Thus these need replacing with longer parts. The part number is 01E301153E. These are around £1.50 for the two of them and they are just pressed in. I removed the old ones with a pair of mole grips easily.

http://www.ecstuning.com/ES267100/

Also there appears to be some longer bolts on the starter motor housing so I bought 2 M12 x 75 bolts which were used to replace the original starter motor bolts.

The flywheel bolts are one time only use and are 12 point spline bolts, I bought some new ones from http://www.carparts4less.co.uk/.

The reverse switch on the 6 speed gearbox is completely different to the 5 speed one. Thus I managed to find a connector that I had that would fit the existing reverse switch and then cut the connector off the car and wired the switch straight to that.
The biggest hassle occurs though with the fact that the gearbox mountings on the 5 and 6 speed car are different. The drivers side is the same however the passenger side is different.
This means you either change the subframe complete or manufacture an engine mounting. As changing the subframe takes a lot longer and required more expense, plus I would have to get the suspension realigned afterwards I decided to manufacture a gearbox mount.

I cut a flat plate from 3 mm steel that you can see on the new gearbox. And welded a plate to a short piece of 50 x 25 steel bar that I had left over from making a trailer. So when the box was fitted and the one mounting in, I just had to measure the length to cut for the bar and then mark the location to weld on the plate.
Here's the finished replacement gearbox support.

Image

And fitted to the car

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Here's a few more photos. You need to get the car up high to get the box out on a drive.

Image

Home made transmission jack. The gearbox weighs around 65-70Kg.

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A ball of string is handy to hold up the various bits and pieces out of the way.

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Karl.
Gone but will never be forgotten
207Bhp 347Lb/ft 14.9 seconds 93mph
The build topic viewtopic.php?f=5&t=56110

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The new 382bhp Audi viewtopic.php?f=5&t=70765

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