MK4 GLI 1.8T _ a daily driver experiment...

[All_Euro]

Other than those few things - been busy chasing a vac leak and tidying up odds and ends...

Had a coolant leak from a pinched o-ring (under the intake mani where the hard coolant pipe attaches to the block under the thermostat) so I replaced that. Tidying up the catch can lines is still on the to-do list but did work on the boost pipes - extended the metal charge pipe above the exhaust mani as much as space allowed as it was barely above the mani. Wrapped the downpipe. Noticed some cracking on the fuel injector wires so I stripped those back and replaced them with the TT clips and protective boots...

[PRY4SNO]

Sucks to hear about the pump being toast. Good that you've got a replacement coming so quickly, hope that solves the problem.

Things are really coming together nicely!

[All_Euro]

A few things have been progressing - slowly but I am at least drifting snowy corners now so picking up from my last post...

Installed and wired up my new precharge pump the other day... rather than order parts and repair the old pump, I just ordered a new one for about $30 extra from a seller named [url="http://www.ebay.com/usr/haldexpart?_trksid=p2047675.l2559"]haldexpart[/url] on ebay. Same guy I bought the Sport Insert from - fellow enthusiast, quick shipping and no funny surprises when the parts arrived.

Re-soldered and shrink-wrapped the wires...




Little wire protection...




Originally I had planned to try full time AWD with pure Haldex fluid (just to see how bad the binding would be) and then to swap in a little LSD friction modifier at a time until the binding went away. Since I was draining fluid to replace the pump, I just exchanged 50ml of the Haldex fluid with the Red Line friction modifier that I have and called it a day. Next time I'll try 30-40 ml instead just to see if a little less will work.

As it is now though, all four wheels are active and I'm getting no binding whatsoever... http://vid340.photobucket.com/albums/o3 ... rlndt3.mp4

[All_Euro]

Finally got the TT brackets out of back seat area - VW brackets still waiting on install. Old brackets would have been 10x easier to take out beforehand of course...




Another one of those things that I'd been meaning to do was replace the lateral links in the rear suspension - finally did that. Really happy with these Madmax adjustable links. Went over them closely before install and the quality appears top notch - build tolerances are excellent...

[All_Euro]

Made some progress on the lower portion of the back seat - drilled the bottom brackets off the GLI pan and welded them in place. There is a U-shaped notch in the sheet metal where each bracket goes - just had to line that up with the centre hole in the bracket and then flush up the bottom edge of the bracket with the bottom of the U. Just getting part of the back seat in cut the road noise in half!

Brackets above U-shaped notches...




Part of the seat belts found their way home...

[All_Euro]

The bottom bracket that joins the seat backs and allows them to split 60/40 needs a little massaging since the TT pan is higher than the MK4 pan - no surprise. With the top layer of metal on this bracket removed and the two top outer tabs snipped, the remaining piece can be bent to fit pretty nicely.

Had to weld in small stages to avoid heating the sheet metal / gas tank area too much - better done beforehand...

[All_Euro]

After the seats were mostly in place, I tried having a little fun in the snow and got nothing but FWD action so I propped the car up on jack stands and all four wheels are spinning... and they accelerate fine with some throttle but when load is applied, the back wheels stop and it's just the fronts turning. There is a bit of a rubbing/skipping sound from the back like the wheels are trying to engage but are slipping out.

Replaced the Haldex fluid just to be sure and the old stuff came out clean - no improvement either so the investigation continued... only one way to find out what’s up.

Pulled the rear diff out...

Drained the Haldex fluid and then removed the controller and pulled the four 15mm bolts that hold the two halves together...


Control module off and top half (with outer clutch plate housing) separated...


Inner & outer clutch discs - part # 02D 525 565 ...


Bottom bearing under the clutch assembly...



Wasn't sure exactly how these clutch discs are supposed to look/feel or what the wear limits are - investigation continued...

[All_Euro]

Pulled the controller apart and the electrical areas were nice and dry - I'm not using them but it's still nice to see the oil is staying where it should. Pulled the electrical pieces off, sopped up the existing oil and blew some compressed air through the oil passages...




Double checked the insert was actually long enough - same dimensions as the original except the 5mm extension at the bottom. When inserted it blocks almost all of the oil passage that the pin in the Regulating Valve normally would...




Pulled the pre-charge pump and Haldex filter just to check - they were both clean. Ran a bit of compressed air through the different exposed oil passages - they were all good. Found a little opening on the bottom of the diff that seems to lead into the bearing area of the bottom of the stack of clutch discs - wasn’t sure if this was a vent or if it should it have a tiny little plug (think mini frost plug) like the one by the Haldex filter. It's in the upper right portion of the picture by one of the bolts that attach the Haldex unit to the differential...




Found a TT owner who said his diff has this same “vent” hole or whatever it is so it must be fine.

[All_Euro]

Checked the pressure limiting valve which was clean. Kept looking and finally found something...


Cleaned the magnet and housing up...

[All_Euro]

Didn't have any success with the various snap-rings so I left the other valves alone for now. Decided to reassemble the coupler assembly and will power the pre-charge pump up once fluid has been added.

Rollers back in their slots...


Thick washer over the rollers and then final thick washer over the discs - you can see the two odd teeth fit in the keyway just right of the bottom centre...


Bearing on top of the stack of washers / clutch discs...


Washer over the bearing with the raised lip inward...



I don't have a Bentley yet but here's a clutch DIY thread I found useful during disassembly / reassembly... http://forums.vwvortex.com/showthread.php?6760419-DIY-for-Haldex-Clutch-Replacement

[All_Euro]

Decided to pull the diff apart while I was at it - just to be sure. Things looked good so I wiped everything down and reassembled a filled with 1.0L of 75w90 - seems to be some confusion online about the actual amount...




Here are a couple good threads that helped during the teardown...
http://forums.vwvortex.com/showthread.php?3350442-Rear-Peloquin-diff-install-how-to&highlight=peloquin
http://forums.vwvortex.com/showthread.php?3463209-Rear-Peloquin-Install-Pics-(56K-)


Once everything was back together, and fluids were filled, I powered up the pump which ran fine... clutches were engaging but not holding under load still. A Vortexer suggested I make a block-off plate to go between the Haldex controller and the main housing - this would test the pump's pressure and isolate the pressure regulating valve. So I made the "plate" out of some thin hard plastic that an unopened tool was packaged in...




Bolted the controller back on and fired up the test rig - finally holding pressure

[All_Euro]

Here’s a flow chart showing how fluid moves through the Haldex Coupler when the clutches are disengaged (green) and engaged (red)...

[All_Euro]

I pulled the controller apart again to have a better look at how much of the Regulating Valve is being blocked by the pin and insert... when the system if fully pressurized, the pin completely blocks off the lower valve opening and covers about 1/2 of the upper opening. The insert blocks about 7/8 of the upper valve opening and leaves the lower opening untouched.

Pin blocking lower valve opening only...


Pin fully extended so the lower opening is blocked and the upper valve opening is about 1/2 blocked...


Pin fully retracted so lower valve opening is clear and insert fully seated is blocking 7/8 of top opening...



So compare these pictures with the flow diagram above - for the clutches to be fully locked, the return path to the accumulator needs to be cut off. As long as the Pressure Limiting Valve is closed, this only happens when fluid is allowed to pass through the top opening in the Regulating Valve. It was pointed out to me that the aftermarket insert is allowing some fluid to escape and since the controller isn't adjusting the Regulating Pin in the valve - the system is only able to partially pressurize the clutches.

[All_Euro]

Kind of helps to see the assembly laid out the same way it's installed in the controller.

Snap Ring - Aftermarket Insert - Regulating Valve - Spring - Regulating Pin - Toothed Plastic Tail for the Adjusting Motor...


I wanted to try to replicate the OEM pin position when the clutches are fully locked - so with the pin blocking the lower opening and about 1/2 the upper opening as well. I found a spare bolt that was about the same thickness of the toothed plastic piece that clips on to the bottom of the pin and then dremelled the head off so it could sit under the plastic tail... I don't have the controller hooked up so the pin can't move anyway.

The "pin extension" is 6mm wide and, in this picture, 11.5mm long. I trimmed is down to 11mm and the assembly seated and locked into place nicely. OEM insert went back in as well...

[All_Euro]

The holes at the top right and bottom left are for bolts but here are how the openings in the controller housing relate to the Regulating Valve - top opening in the valve feeds the top and bottom openings in the housing. Lower opening in the valve feeds the middle opening in the housing which is where the point of the awl is...






So with the lower opening in the valve or the middle hole in the housing blocked, full pressure / clutch lock should happen. The initial test went well - the clutches locked up as I was hoping... will try again tomorrow and then hopefully install and test for real.

[All_Euro]

Stepped out into my garage to install the diff...




Install went well and the subsequent test drive resulted in some tail-happy cornering... nearly shed a tear I was so happy. Really slow U-turns are a touch grabby. It's minor but it is there so I'll add a bit of viscosity modifier to the Haldex oil when I have a chance.

[All_Euro]

Made some progress on the exhaust - I decided on race mufflers for their straight through design but used two (a smaller one after the resonator and a bigger one just before the tail-pipe) to get the sound levels down to where I want them.

Pipe clamps made from two pieces of steel angle and a pair of bar-clamps I had...


Ran just the resonator and small muffler for a while...


Made the bends around the differential and got the exhaust a little closer to the exhaust cut out...


Here’s an OEM mid-span bracket that didn’t make it into my parts pile somehow. Might buy one to see if it will work - PN: 8N0253461C...


Stainless hanger positioning at the back muffler was probably the fussiest part of the exhaust fab - have one on each end of the muffler...


Muffler secured in position with tail-pipe centred in the cut out...



Still need to weld in some mid-span hangers and the exhaust tip but it’s getting pretty close. The stainless Torco clamp behind the muffler is pretty lame compared to the OEM sleve-clamps so I’ll swap it out - it doesn’t seal completely and is pretty thin. The exhaust is really close to the CV boot on the driver’s side of the diff so I’ll put some heat wrap on that too.

[PRY4SNO]

Wow man, nice update. Things are looking good.

What do you have to do differently when you hook up the Haldex controller, to make sure everything works right?

I think I'll have to get you to glue my temp exhaust together before I get one from Unobtanium Looks really neat and tidy!!

[scubagli]

Nice.

Sent from my SAMSUNG-SM-G870A using Tapatalk

[All_Euro]

Thanks guys.

The controller isn’t hooked up at all - just sitting there in case I want to hook it up. I might do that if I can’t get rid of the light binding during parking lot manoeuvres. Not sure how to get around this yet but I’d prefer all the wheels be active all the time instead of just when a sensor tells them to be.

The exhaust is getting close but it’s definitely not show quality - come by any time and I’ll give you a hand

[All_Euro]

Had my heat-exhanger implode a while back and the engine oil emptied into the cooling system... thankfully I had a spare from the TT 225 that I could swap in. I'd estimate that it only took a hundred thousand flushes or so to clean out the system...




Haven’t been doing much to the car except driving it but I did get some of the trunk interior bits trimmed to fit the raised floor..

[All_Euro]

Went to Safeway the other day and came outside to this...








Hustled home to seal things up from the rain...






Currently negotiating with insurance for a market value payout instead of their dubious book value

[lorge1989]

Im glad I dont' have to deal with crazy hail like that! Sorry to see it happen to anyone... I assume you will just buy the car back and keep driving it?

[PRY4SNO]

But... how do they assign a value to a 1/1 car in the country (possibly continent)?

Hope this gets resolved in your favour, I'm sure you'll be able to use documentation to your advantage.

[ringbearer]

Sucks!

Just think of them as "speed dimples"