Clutch and flywheel removal, rear main oil seal replacement - mk3

Nov 10, 2013
Clutch and flywheel removal, rear main oil seal replacement - mk3
  • Mk3 clutch or flywheel removal and rear main oil seal replacement, for VW Jetta TDI and Passat TDI
    difficulty: 3/5
    back to 1000q: mk3 FAQ and "how to" index"


    Introduction

    This article gives tips on removing the clutch/flywheel and replacing the rear main oil seal.
    Most Jetta and Passat were built in the mid/late 90s, used as daily drivers, and have high miles by now so it couldn't hurt to replace the seal if the clutch is being serviced. The only additional step is flywheel removal. This project is rated 3/5 difficulty only because it requires transmission removal - once the transmission is out it's a very easy job.

    Here are some more notes on clutch replacement in the forum

    There are two types of rear main oil seals (RMS) on the mk3 TDI, rubber lipped with spring or the flat paper-like teflon/PTFE seal. The rubber RMS has two lips and has a metal spring on the inside edge. The disadvantage of the rubber spring type is that if there's already a groove worn into the crankshaft from the old seal, this seal may not seal it completely unless it sits into the same groove.

    The teflon type (pictured below) is a papery-plastic like seal with no metal spring and should be applied dry with no oil. Most replacement parts will be telfon. The advantage is that it has a wider lip that sweeps across the running surface of the crankshaft and leaves no groove. If there is a groove, the seal can "bridge over" a small groove and seal better than a rubber type. Teflon seals are also more durable and slippery. Although a teflon seal can be more difficult to install, your RMS should come with a plastic guide sleeve installation tool. It only fits one way and guides the RMS onto the crankshaft by stretching the seal a little bit for installation.
    [​IMG]

    Related links: 1000q: transmission removal for mk3 TDI , 1000q: general TDI clutch FAQ

    Parts and tools for rear main seal replacement
    12 point sockets
    10mm sockets
    torque wrench
    flywheel holder (or make your own)

    6x 12 point bolts (one use only) VW# n 902 061 03
    6x flywheel bolts (one use only) VW # n 101 010 01

    For rear main seal replacement
    T-40 torx
    rear main seal VW # 028 103 171 b OR rear main seal VW # 068 103 171 f
    oil pan gasket VW# 044 103 609 d

    misc notes and optional part list
    The stock clutch was a 228mm sachs clutch with a solid flywheel. The clutch and pressure plate (and part number) is specific to the TDI.
    stock pressure plate VW# 044 141 025 x or #074 141 025 b
    stock clutch VW# 028 141 035 c or 028 141 035 bx
    stock flywheel VW# 028 105 269 b (rebuilt so it has an "x" suffix)
    clutch pivot ball pin VW # 02a 141 777b
    clutch fork VW# 02j 141 719 c
    clutch fork spring VW# 012 131 741
    release bearing is VW# 02a 141 165 g

    vr6 clutch kit (no flywheel)

    Procedure
    Clutch/flywheel removal
    Remove the transmission. See 1000q: transmission removal for mk3 for more details. I don't suggest using air tools inside the bellhousing since it blows clutch dust all over where it can be inhaled. Use a wet rag to wipe off the dust.

    To remove the pressure plate, use a 12 point socket to remove the 6 bolts. Below is a picture during installation, the bolts were already removed. I put a socket in the middle of the clutch to align it. Since this picture was taken during installation, you can see the CV joint covered with plastic wrap to keep it clean.
    [​IMG]

    To remove the flywheel, counterhold the flywheel and remove the 6 bolts holding the flywheel. Do not counterhold it by the 19mm bolt at the harmonic balancer/serpentine crankshaft bolt at the other (front) end of the crankshaft. It's ok to use that bolt to gently turn over the engine but it's a 1 use only stretch bolt and you don't want to use the crankshaft to counterhold when there is a correct way.

    To counterhold the flywheel, thread some of the transmission bolts back into place, use a VW specific flywheel tool (a lock that bites the flywheel and threads into 1 bolt hole), or a generic flywheel holder (pictured below with the breaker bar on it). The flywheel will only bolt on at one orientation due to the bolt hole alignment. An offset bolt makes sure that the TDC mark is at the correct spot. If you are installing a new flywheel, make a mark on the engine to note where TDC is. This lets you double check the position of the TDC mark on the new flywheel against the old flywheel.
    [​IMG] [​IMG]

    An easier way to counterhold the flywheel is to use a holder made to fit the teeth and bolts on the car. Dieselgeek.com sells a flywheel holder desiged for this engine and tooth spacing. Below is a thumbnail, click to enlarge.
    [​IMG]

    As mentioned in 1000q: clutch FAQ, the TDI clutch is pretty robust and the flywheel on my car (street use only) did not show much wear when I removed it. Although a dual mass flywheel (DMF) and clutch kit could replace your single mass flywheel, I don't think it's a good idea due to cost and reliability. I reused the single mass flywheel by scrubbing it with scotch-brite pads and then thoroughly cleaning it with brake cleaner. Disclaimer - this was what I chose to do on my car only, have your flywheel inspected by a professional for cracking, warping, and hot spots. You may need to have it resurfaced with a grinder stone before attempting to reuse it. Don't use a lathe to resurface a flywheel since it can skip over the hardened spots. Before putting it back on, I marked the TDC notch with paint for easy identification.
    [​IMG]

    For installation, use all new flywheel and pressure plate bolts.

    You can put a very thin smear of high temp grease on the splines. If in doubt, less is better since you don't want grease on the clutch. Wipe down the flywheel and pressure plate surfaces with brake cleaner before installation to remove machining oil. Again, the flywheel bolt holes will only align in one position so that the TDC mark is in the correct position. The VW flywheel bolts come with threadlocker, I would also suggest medium strength threadlocker on the pressure plate bolts since you don't plan on removing it soon.

    flywheel bolt torque: stage 1: 22 ft-lbs. stage 2: 44 ft-lbs. final stage: additional 1/4 turn (90o turn)
    pressure plate bolt torque: hand tight, then tighten diagonally or in a pattern, in stages, to a final torque of 15 ft-lbs. Tightening the bolts in stages like 2 turns each bolt in a star pattern diagonally across the pressure plate keeps it flat while tightening.

    Rear main seal removal
    Remove the shield (3x 10mm bolts) circled in yellow below.
    [​IMG]

    Remove the RMS flange. It uses (2x T40) torx bolts on the oil pan. Do not pry close to the flange surface! The area outlined in red is a safe place to pry it out.
    [​IMG]

    Below is the end of the crankshaft exposed. Note - I didn't cover the CV joint with plastic wrap because I was going to replace it anyways (the earlier picture with plastic wrap over the joint was taken during installation). Scrub away any corrosion on the block and wipe clean. The correct method to replace the RMS flange is to remove the oil pan, install the rear main seal, and then install the oil pan with a new oil pan gasket. This ensures that the flange is sealed correctly at the corner. I put some gasket maker at the corners before putting the new flange in and there are no leaks.
    [​IMG]

    Scrub the rust off with scotch brite and wipe clean.

    There was a paper gasket in the ETKA (the VW parts catalog) that goes under the flange but during removal, mine didn't. The replacement flange had a rubber seal against the engine block. If your situation is the same, I would not use the paper gasket.

    If you are using a teflon type seal, install it dry (no oil or grease) and always use the install guide sleeve to prevent damage to the seal. From what I've heard, teflon works better on diesels so don't worry if you had a rubber-spring type seal and were sold a teflon seal.

    Torque for the rear main seal flange is 7 ft-lbs. There is no torque listed in the bentley manual for the oil pan-rear flange torx bolts so use an educated guess.

    Have more questions about the Clutch, rear main seal, or kits on a Volkswagen Jetta and Passat? Please post your comments in the myturbodiesel.com forums