Mk4 01M Spedometer Drive Gear DIY

[Vin_Maddux]

I've been searching high and low and have not found a DIY for spedometer drive gear replacement. I can't even find the procedural detail in the Bentley manual:

• Volkswagen > A4 > 1999-20064 speed automatic transmission 01M, 39 - Differential, Removing and Installing
  
• 2 - Speedometer drive With marking for oil level indication [Speedometer drive ]
  
• Speedometer drive - With transmission installed, check gear oil in final drive Final Drive Oil, Checking .

My symptom: spedometer starts twitching at approx 65-70mph and cruise control hunts. Tachometer and other gauges are stable and don't bounce while this is happening.

I've been told that the spedometer drive gear on the Mk4 01M automatic is known for this.

I was able to find the VW part: Mfg#: 01M409187 and am hoping to replace it, drain the final drive oil in the hope of removing the plastic debris and changing the differential gear oil for maintenance.

Any suggestions/tips are greatly appreciated.

[CoolAirVw]

there is no "how to" that I know of.

This is a very large job for such a small problem. For $89 dollars you can get a GPS that will show your speed.

Also there are other things that can cause this.

Note: I realize on cruise control it will probably jerk around with this problem but still the cost of replacing the speedo drive gear would be very large if a shop did it, and it would be difficult for a DIY to get done.

[Vin_Maddux]

Thanks again for the reply. I see in your signature that you are a master ASE so I appreciate your advice. I'm also very mechanical so if you reply to my posts I'd appreciate it if you were to be technical.

1. GPS = NO WAY that's happening
2. Big Job = I know this and am about to do the CV axles anyway. I've been living with this for a while. I understand that this spot is accessible when the CV axle is out. I can't remember which side but I want to say driver. I'm also aware that the Vehicle Speed Sensor can do this and will be replacing that as well.
3. Tools = I have the correct tools to do the work. All of them but a VAG-COM and am thinking hard about that.
4. Fast = Nope, but I am very thorough and enjoy mechanical work. I was a marine diesel mechanic as a young man.

I'm hoping for a few tips from someone who has replaced one. Anyone?

[Stangrcr1]

The speedometer drive gear is driven from a plastic gear on the differential.

I replaced the gear on the differential while rebuilding my tranny because the gear was cracked. It requires trans removal from the car, remove the rear cover, unscrew the bearing retainers(special tools which you probably don't have), pull differential, pull bearing off differential, then the gear can come off.

Reinstalling the diff is easy until you get to the bearing preload adjustment and pinion alignment. Without the special tools, I wish you luck. Been there, done that. If not properly done, your diff will live a short life.

BTW, I am ASE Certified Master Auto Tech too.

[vdubtech398]

The speedometer drive gear is driven from a plastic gear on the differential.

I replaced the gear on the differential while rebuilding my tranny because the gear was cracked. It requires trans removal from the car, remove the rear cover, unscrew the bearing retainers(special tools which you probably don't have), pull differential, pull bearing off differential, then the gear can come off.

Reinstalling the diff is easy until you get to the bearing preload adjustment and pinion alignment. Without the special tools, I wish you luck. Been there, done that. If not properly done, your diff will live a short life.

BTW, I am ASE Certified Master Auto Tech too.

You do NOT have to remove the trans or rear cover to replace the plastic speedo gear or the diff. remove the axle and bearing cap. mark and count the turns on the bearing cap. Remove the bearing on the end of the diff with the metal ring/retainer, then R&R plastic gear and re-install. NOTE: it requires a few different pullers/mechanical intuition to remove the bearing and the metal ring without damaging things. If you ruin the bearing then the cover and diff may have to come out. Last one i did took 2 hours. Order the metal ring that locks the plasstic gear on the diff just in case you damage it removing it.

[Stangrcr1]

You do NOT have to remove the trans or rear cover to replace the plastic speedo gear or the diff. remove the axle and bearing cap. mark and count the turns on the bearing cap. Remove the bearing on the end of the diff with the metal ring/retainer, then R&R plastic gear and re-install. NOTE: it requires a few different pullers/mechanical intuition to remove the bearing and the metal ring without damaging things. If you ruin the bearing then the cover and diff may have to come out. Last one i did took 2 hours. Order the metal ring that locks the plasstic gear on the diff just in case you damage it removing it.

Exactly the reason I would remove the trans. Much easier to pull the bearing with the diff out. And not everyone has those pullers.

[vdubtech398]

Exactly the reason I would remove the trans. Much easier to pull the bearing with the diff out. And not everyone has those pullers.

If you dont have to pullers and some special tools it would be difficult. I was just throwing that option out there..

[Vin_Maddux]

Okay,

First, thanks to everyone for their input. I can see that I'll have to plan this carefully so as not to screw it up. I can now see where the first post was coming from when he said this is not trivial.

I'm inclined to attempt the plastic drive gear replacement with the differential in and will pull it as Stangrcr1 suggested if I get in trouble. Matter of fact, if I have transmission/differential out, it seems like it would be smart to rebuild them since the car has 180k miles on it.

vdubtech398, are you talking about the final drive axle flange and that cap/bearing?

Bentley:
Volkswagen > A4 > 1999-2006
4 speed automatic transmission 01M
39 - Final Drive, Differential

Special tools, testers and auxiliary items required:
Drive flange fitting appliance VW 391
Oil seal extractor lever VW 681
Puller 3109
3319 Thrust piece
Torque wrench VAG1331
Kukko 18/0 Puller
Thrust plate 40-105
Tapered roller bearing puller V.A.G 1582
Extractor tool V.A.G 1582/3
Torque wrench VAG1576
http://www.toolwarehaus.com/VW%20TOO...RS%20(OLD).asp
http://www.samstagsales.com/vwaudi_ref.htm

Spedometer Drive Gear job: OE Auto Parts should run around $125.00
Spedometer Drive Gear: 01M-409-187 (Is this the plastic gear that breaks or is it the input gear?)
I can't find the flange cover that gets bent during removal that vdubtech398 warned of
Bushing: 095-409-190
Roller bearing: 002-517-185-A095-409-259 (any harm in replacing the bearing if it is out?)
Seal inner/outer kit: 020-489-085G
Anything missing? Who has cheapest OE parts?

[vdubtech398]

Okay,



vdubtech398, are you talking about the final drive axle flange and that cap/bearing?

yupp

[Stangrcr1]

Okay,

I'm inclined to attempt the plastic drive gear replacement with the differential in and will pull it as Stangrcr1 suggested if I get in trouble. Matter of fact, if I have transmission/differential out, it seems like it would be smart to rebuild them since the car has 180k miles on it.

I rebuilt the daughter's 01M only because I was rebuilding the VR6 due to a blown head gasket, bad chains, etc at 157k. Glad I did as one of the clutch packs was going out and one solenoid bad. I just happened to find the cracked speedo gear during the rebuild.

[CoolAirVw]

It is possible to do it without pulling the trans. But removing the "k" member that supports the rack and pinion would be absolutly neccessary.

With axles and k member and pulling diff ect. this makes for a big job. Putting the diff back together, and getting the preload correct on the bearings is a must. You could end up with failing bearings or a gear whine ect if its not set up properly.

[vdubtech398]

It is possible to do it without pulling the trans. But removing the "k" member that supports the rack and pinion would be absolutly neccessary.

With axles and k member and pulling diff ect. this makes for a big job. Putting the diff back together, and getting the preload correct on the bearings is a must. You could end up with failing bearings or a gear whine ect if its not set up properly.

like i said i have done it with only removing the axle off of the trans, the flange, the bearing cap, the bearing and then the speedo gear with the metal ring it locks into. If you count the turns of the bearing cap and mark it correctly and re-install it the same way it came off, and removed and install the bearing (old bearing) on the diff correctly without any damage the pre-load will be the same as it was before the repair. special tools are a must.

[CoolAirVw]

I'm not arguing...

But what car did you do it without pulling the K member? On the ones that I've fixed, there was 1/2 inch of clearance between the pan and the K member. No way the diff could fit in 1/2 inch and come out. Ring gear on the diff is 6 inches in diameter.

Sorry to be so negitive but Diy'ers attempting major work like this alot of times dont work out. I usually put something like "I love this thread" or "I love threads like this one" in threads where folks attempt rebuild or major work and cant get it right. I've been doing this for quite awhile.

If your a pro mechanic or maybe a real serious Diy'er then dive on in. matter of fact you can do it, take a bunch of pics and make a DIY thread documenting how, and then the next guy will have the info.

[vdubtech398]

I'm not arguing...

But what car did you do it without pulling the K member? On the ones that I've fixed, there was 1/2 inch of clearance between the pan and the K member. No way the diff could fit in 1/2 inch and come out. Ring gear on the diff is 6 inches in diameter.

Sorry to be so negitive but Diy'ers attempting major work like this alot of times dont work out. I usually put something like "I love this thread" or "I love threads like this one" in threads where folks attempt rebuild or major work and cant get it right. I've been doing this for quite awhile.

If your a pro mechanic or maybe a real serious Diy'er then dive on in. matter of fact you can do it, take a bunch of pics and make a DIY thread documenting how, and then the next guy will have the info.

I totally agree. Its a envolved job. I'm not arguing either. im sure you've been doing this way longer than i have. I've been a VW tech for 6 years and will be master certified in the next 2 or so. Here at the dealer we dont do as much tear down on automatic transmissions as im sure you do. More or so R&R for major internal problems. But i am pretty familiar with trans operation and diagnosis. I was just trying to clarify the exact way that i have done it and well continue to do it (Plastic speedo gear reaplcment on 4 speed 01M). The last couple i did were on 2002 jetta 2.0L with a 4speed 01M trans. I dont take the subframe ( K) member out because i do not remove the differential or the pan cover from the trans. I do all the work thru the bearing cap of the passenger side of the trans. Not arguing. Next time i will try to take some pics for a DIY or something. Cheers man

[Vin_Maddux]

Okay,

Let's try to be positive here. CoolAirVW has posted negative comments on other threads dating back to 2005. Honestly, didn't come looking for negativity. -Maybe CoolAirVW should just take me at my word when I say I was once a Marine Diesel Mechanic. Most mechanics are "fixers" and like helping people. I was once a mechanic and ended up in Information Technology by fate. I'm not in here saying I have daily skills. I am saying I love working on stuff and helping people. -Anybody who has posted on this thread can get Enterprise Grade IT consulting advice from me for free whenever they want it. For example, I'm running my Bentley reader on 64bit Windows 7.

-As for clueless DIYers, some are at least smart enough to get advice from people who have daily Audi/VW skills... Again, I really appreciate the input from all (including CoolAirVW). The idea here is to have fun and maybe come up with a nice advanced DIY for those who dare.

I've heard other mechanics besides vdubtech398 say they've fixed this issue by going through the flange on the differential. It's the only cost effective approach in my opinion. For what it's worth, the Bentley IMPLIES doing this. It's an excellent flat rate technique and the bearing cap mark and finesse with the bearing press is what requires the "Mechinical Intuition" vdubtech398 spoke of. Understood. Kudos to vdubtech398 for being positive and sharing some flat-rate skills with other mechanics and DIYs.

-The hard part is doing the first one without having watched one being done. Risky, but since I was born with a wrench in my hand and was using lathes and mills by age 14, I give myself at least 70/30 in my favor if I take my time with planning.

Here's how I see it. It makes sense to get into this if the special tools and parts run less than $450 That's about %25 of cost for a fully remanufactured 01M for R&R. My backup plan is to be prepared to pull the transmission and make final drive adjustments if they can't be made with transmission in. Additionally, will have set aside $1750 to buy a remanufactured 01M in case of Epic Fail DIY Disaster. I understand that is a possible outcome and we've all screwed up a few things. Hopefully not the same thing twice...

I'm new to using a Bentley reader and haven't found the broken plastic gear inside the differential yet. Anyone know what it is called in Bentley? Better still, the part number for it and the clip?

It is clear that one needs to fully understand what measurements/adjustments are necessary to succeed. There are three: Input Gear, Pinion Gear, Diiferential
Bentley: Volkswagen > A4 > 1999-2006
4 speed automatic transmission 01M
39 - Final Drive, Adjusting

Adjusting after Replacing Components
When working on the transmission the following components only require adjustment if individual components have been replaced that directly affect the final drive adjustment. To eliminate unnecessary adjustments observe following table: (table of fix this adjust that)

So for adjustment disasters, looks like we're talking about the diferential adjustment which is performed after servicing Supporting ring, park lock gear or bearing cover (adjusting ring)?

As for Adjusting Ring marking, will mark and count turns but will also measure it with a depth guage before removing and after placement with 3155. This provides tolerance good to .01mm (.005in), which is about one tenth of the smallest adjusting shim. Bentley: "Mark adjusting ring: If used bearings are re-inserted, mark installed position - arrow - and again position on marking when installing."

When required parts are exactly identified, start narrowing down which special tools you have and which are need. Probably won't need everything on the list. 3109, 3155, 3319 and Kuko 18-0 (I have equivalent) look like must haves.