# DIY: Bearing replacement



## mattgreeneva (Apr 5, 2006)

*DIY: Crank/Rod Bearing replacement*

*NOTE: I AM NOT RESPONSIBLE FOR YOUR MISTAKES. this worked for me. It should work for you*
I havent seen any DIY's on this and I know its always nice to have something to go by so here we go.
Tools:
Main Cap bolts: 17mm
Rod Cap nuts: 14mm
Torque Wrench
- Main Cap bolts 48 ft.lbs 1/4 turn (per bentley)
- Rod Cap nuts 23 ft.lbs 1/4 turn (per bentley)
Assembly lube
NEW rod, crank, thrust bearings








start out with removing the oil pan, flywheel assembly, etc until it looks like this








loosen your main cap bolts








i found it easiest to leave 1/4 pistons down and 2/3 up then loosen rod cap nuts








start removing the main caps MAKE SURE YOU DOO NOTTTT get them mixed up. they need to go on exactly the way you took them off








after that remove the rod cap nuts same thing DO NOT mix them up








remove your crank and sit it in a safe location.check the crank for scaring or any marks that shouldnt be there. if your crank is damaged you will want to have a machine shop turn it for you and get it back the way it should be.








remove all of the old bearings. they should just slide right out with a little prying with your finger nails. using the assembly lube go ahead and coat the new bearings.








i started with the rods and put the new lubed up bearings on. there is a slight groove on the bearing and the rod where they sit. its unmistakable so you should be fine noticing it.








after that is done go ahead and coat your main bearings and do the same thing. there are 2 different kinds of main bearings, tops and bottoms. (remember the motor is upside down in my pictures) but the tops have little holes and valleys that line up with holes on the block. these are to keep the bearings properly lubed. so make sure you use the correct bearings when replacing. at this time also install the top part of the thrust bearings on cap #3 (i failed to take a picture of them... but again its self explanitory)








now your ready to sit your crank back in. i did it alone but it might be easier if you have someone there with you to move the rods into positions








now you can install the bottom part of the rod bearings on the caps and place them back on. same as before they seat in a little groove that you will easily see. remember to put them on EXACTLY the way you took them off








after that do the same thing with your main caps and re-install the bottom thrust bearings. 
your finished product should look exactly like it did when you started. 
again as stated above torque your rod/main caps to spec. 
- Main Cap bolts 48 ft.lbs 1/4 turn (per bentley)
- Rod Cap nuts 23 ft.lbs 1/4 turn (per bentley)
replace your oil pump, pan, accesories, etc and your on your way
again... take your time, pay attention, and happy tuning.
if i forgot anything or you know of some special tricks or have any questions let me know and i will modify this post as needed.
http://****************.com/smile/emthup.gif 



_Modified by mattgreeneva at 8:15 PM 4-18-2009_


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## 84_GLI_coupe (Apr 3, 2001)

*Re: DIY: Crank/Rod Bearing replacement (mattgreeneva)*

You never set your crank end play (main bearing thrust clearance)!!
- torque all main caps but the center cap
- center cap should be installed and seated, bolts should be threaded but loose
- using a dead-blow hammer (rubber mallet, etc), hit the flywheel end of the crank directly in line with the axis of rotation, then hit the timing belt side in the same manner, then hit the flywheel side again
- place dial indicator on flywheel flange of crankshaft
- using a big flat head screwdriver wedged between one of the torqued main caps and the crank counterweight, move the crankshaft along its axis in either direction
- total movement of the crankshaft should be 0.003", check Bentley for tolerances
- torque center main cap to spec
- re-check crank end play with dial indicator, should still be 0.003"


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## teraance roush (Mar 26, 2003)

*Re: DIY: Crank/Rod Bearing replacement (84_GLI_coupe)*

nice catch was just about to post!


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## TMTuned99.5Golf (Jan 27, 2004)

*Re: DIY: Crank/Rod Bearing replacement (teraance roush)*

On the bolts.... all those are *stretch*, hence the added 1/4 turn at the end.
It about $19 for main bearing cap bolts and $40 for the rod bolts but those are generally pressed in. 
If you re-use the same bolts you risk allowing them to come closer to premature failure. With something as critical as the motor, it may be just me but it's cheaper to fix it now than it is later.

__
Image uploading. Refresh page to view


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## onewiper (Aug 29, 2002)

Should always install main bearings first, check endplay, then install rods.


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## elRey (May 15, 2001)

*Re: DIY: Crank/Rod Bearing replacement (mattgreeneva)*


_Quote, originally posted by *mattgreeneva* »_ using the assembly lube go ahead and coat the new bearings.









One thing I've never seen specifically mentioned is whether you lube both sides of a bearing or just the inside.


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## spitpilot (Feb 14, 2000)

*Re: DIY: Crank/Rod Bearing replacement (elRey)*

You lube just the inner face and face of journals..that had better be all that's moving past each other..or you've spun a bearing! Didn't see any Plastigage action goin on either...always good to Plastigage B4 tear down to check for journal taper..too much taper and you're wastin your time changing bearing shells..then Plastigage each bearing on install..sometimes parts get mixed up and you'll get half a bearing of the wrong size..it only takes a few mins to do the checkin! http://****************.com/smile/emthup.gif


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## mattgreeneva (Apr 5, 2006)

*Re: DIY: Crank/Rod Bearing replacement (spitpilot)*

i guess i suck then lol. 
i didnt buy new bolts








but i did set the crank, a friend mentioned it before i put it back together. i didnt do it quite like that. but since nobody posted on this thread i just let it go. 
but since it was already posted im not going to bother re-writing it. thanks for the input


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## elRey (May 15, 2001)

*Re: DIY: Crank/Rod Bearing replacement (mattgreeneva)*

Sorry, my comment wasn't directed at you specifically, but to all bottom-end build articles in general.
I enjoyed your DIY http://****************.com/smile/emthup.gif


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## Pitsy (Oct 27, 2007)

*Re: DIY: Crank/Rod Bearing replacement (mattgreeneva)*

Not bad. I always put some plastic tubing over the rod bolt threads whenever they're exposed. Don't want to scratch the crank.


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## spitpilot (Feb 14, 2000)

*Re: DIY: Crank/Rod Bearing replacement (Pitsy)*


_Quote, originally posted by *Pitsy* »_Not bad. I always put some plastic tubing over the rod bolt threads whenever they're exposed. Don't want to scratch the crank.

Yup...that trick was in the old...talking 60 years old here..Motor Manual...the "mechanic's bible" that covered all cars on the road (only US iron at that point in time) in just one 2" thick volume!!!...B4 lawyers got hold of things and demanded zillions of pages of CYA stuff in every manual!


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## mattgreeneva (Apr 5, 2006)

*Re: DIY: Crank/Rod Bearing replacement (mattgreeneva)*

got it running today. no knocks.. good news


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## Bicycle019 (Mar 30, 2001)

Bump for good info, used along with Bentley to rebuild an ABA bottom end.


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## vanagonnut (Jul 14, 2016)

onewiper said:


> Should always install main bearings first, check endplay, then install rods.



I'm in the middle of an ABA rebuild.

I imagine the end play spec is in the A3 Bentley but I don't see any procedure (leave #3 main cap loose etc., hit end of crank etc) shown in Bentley.
I do see this type of procedure in my Mk2 Haynes. But the center bearing is of a different design.

End play is adjusted via using different thickness shims on each side of #3 main bearing? OR, is it actually adjustable?

Thanks

Neil.


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## Butcher (Jan 31, 2001)

Usually you do not need to make an adjustment. If it's out, the bearings are worn [unlikely since they are new] or the crank is worn. If the crank is worn, then most likely it's from a manual transmission car. 

You could make shim using shim stock. I have never seen shims sold separately. Call the machine shop and they would know more than I.

As for lubricating the back of the bearings, that will not cause a bearing to spin. The bearings are locked into position and if they did spin, it's not because of any oil in the back. The reason you do not want to have anything behind the bearing is so bearing dimension will not change. The oil will change the diameter of the bore [slightly].


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## vanagonnut (Jul 14, 2016)

thanks

re: rod orientation. Dimples face towards pulley end of engine correct? Online tech references refer to "engine front". Does this term refer to side of engine with oil cooler?

I was curious about difference in shim wear auto vs manual tranny 2.0.
Original end play shims don't look overly worn but then as a newb, my POV is limited on this.

I'll double check wear marks on old shims, but do all 4 end play shims mount with grooves facing out toward each end of engine? I'd think that helps with oiling.
Can't see those details in A3 Bentley but A4 Bentley shows some detail for 2.0 which seems counter intuitive (oiling)
Sorry for crap pic. Shims as currently installed. All 4 have grooves facing outward:










From A4, end play shims (AEG?)


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## Mr.loops (May 27, 2010)

> I was curious about difference in shim wear auto vs manual tranny 2.0.


This article mentioned several causes of thrust bearing wear, but did not get into detail which type of transmission (manual vs. auto) had a larger impact. http://www.4secondsflat.com/Thrust_bearing_failures.html 

*External overloading due to.

a) Excessive Torque converter pressure.

b) Improper throw out bearing adjustment.

c) Riding the clutch pedal.*

I found this interesting regarding excessive VD on the ground side and thrust bearing wear

*Other External Problems. Aside from the items already mentioned, there is another external problem that should be considered. Inadequate electrical grounds have been known to exacerbate thrust surface wear. Excessive current in the vehicle drive train can damage the thrust surface. It affects the thrust bearing as though the thrust surface on the crankshaft is not finished properly finished (too rough). Excessive voltage in the drive train can be checked very easily. With the negative lead of a DVOM connected to the negative post of the vehicle battery and the positive lead on the transmission, there should be no more than .01 volts registering on the meter while the starter is turning over the engine. For an accurate test, the starter must operate for a minimum of four seconds without the engine starting. It is suggested to disable the ignition system before attempting this test. If the voltage reading observed is found to be excessive, add and/or replace negative ground straps from the engine to the vehicle frame and transmission to frame until the observed voltage is .01 volts or less. Note: Some systems may show a reading of .03volts momentarily but yet not exhibit a problem. For added assurance, it is a good idea to enhance the drive train grounding with larger battery cables or additional ground straps.*


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## vanagonnut (Jul 14, 2016)

Mr.loops said:


> *External overloading due to.
> 
> a) Excessive Torque converter pressure.
> *


*

hadn't thought of that. Thanks. I'd still lean toward a donor engine from an automatic Mk3, Mk4, most folks leave the clutch pedal pushed down at stop lights, but any engine can be abused.
The one I'm rebuilding came from an automatic. Thrust shims look "ok" in spite of some pretty torn up pistons (excessive wear at all skirts). 170K miles.*


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## Mr.loops (May 27, 2010)

> Most folks leave the clutch pedal pushed down at stop lights, but any engine can be abused.


I'm sure there are more thrust bearing issues due to human error than due to component failures/set-up - but who knows 



> The one I'm rebuilding came from an automatic. Thrust shims look "ok" in spite of some pretty torn up pistons (excessive wear at all skirts)


It's too bad you didn't measure the axial crankshaft "play" while it was still in the block. I would feel more comfortable doing this test than just performing a visual check on the thrust bearing.
Even when your re-assembling a rebuilt engine, be sure to confirm that your thrust bearing fitment is within spec.


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## vanagonnut (Jul 14, 2016)

Mr.loops said:


> It's too bad you didn't measure the axial crankshaft "play" while it was still in the block. I would feel more comfortable doing this test than just performing a visual check on the thrust bearing.
> Even when your re-assembling a rebuilt engine, be sure to confirm that your thrust bearing fitment is within spec.


I'll be measuring end play.

Do #3 main cap bolts have to be loose to do this? (I think not since engine has thrust shims and not a saddle type bearing in lieu of the shims. i.e. the older style 1.8 8V)

Thanks.


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## Mr.loops (May 27, 2010)

vanagonnut said:


> I'll be measuring end play.
> 
> Do #3 main cap bolts have to be loose to do this? (I think not since engine has thrust shims and not a saddle type bearing in lieu of the shims. i.e. the older style 1.8 8V)
> 
> Thanks.


I don't know off hand but my Bentley will 
I'll be happy to pass on the specs and procedure for you when I get home tonight 

What engine code do you have?


Sent from my iPhone using Tapatalk


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## vanagonnut (Jul 14, 2016)

Mr.loops said:


> I don't know off hand but my Bentley will
> I'll be happy to pass on the specs and procedure for you when I get home tonight
> 
> What engine code do you have?


ABA and thanks for offer.

I don't see mention of #3 main cap bolts and end play check in my A3 and A4 Bentley manuals but then
it wouldn't be the first time I've missed a text detail. 

I don't think any 2.0 Mk3 engines use the older style saddle bearing at #3 main journal, so I hope I'm not confusing matters here, but
I'll take a pic of the Haynes text I'm referring to.

Neil.


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## vanagonnut (Jul 14, 2016)

vanagonnut said:


> I don't think any 2.0 Mk3 engines use the older style saddle bearing at #3 main journal, so I hope I'm not confusing matters here, but
> I'll take a pic of the Haynes text I'm referring to.
> 
> Neil.


what I read and referred to but doesn't apply to ABA; I'm *pretty sure* it only refers to old style saddle type thrust bearing













old style saddle type thrust bearing (ABA bearing has NO saddles. Thrust shims take the place of saddles)















Use this procedure to check end play check on an ABA? I see "axial side play" specs but no procedure section 13 in A3 Bentley.


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## Mr.loops (May 27, 2010)

> I don't see mention of #3 main cap bolts and end play check in my A3 and A4 Bentley manuals but then
> it wouldn't be the first time I've missed a text detail.


In the Bentley manual for the Mk3's on page 13-12 ( in the front of the book) it states that for the ABA engine, the crank axial play should be between 0.07 mm - 0.17 mm. 



> I don't think any 2.0 Mk3 engines use the older style saddle bearing at #3 main journal


There are two types and you can pick either:

Conventional thrust bearings where the flanges are incorporated into the journal bearing - just 2 assembly's. This seems to be a preferred choice due to the ease of installation. The one problem with this design is that is starves the bearing of oil which leads to premature wear/failure.

Journal bearings with two separate thrust washers. More assembly work but you have better oil flow/retention


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## vanagonnut (Jul 14, 2016)

Mr.loops said:


> In the Bentley manual for the Mk3's on page 13-12 ( in the front of the book) it states that for the ABA engine, the crank axial play should be between 0.07 mm - 0.17 mm.
> 
> 
> 
> ...


Thanks. Yes. Found the end play specs. Using a dial gauge, found that end play is pretty tight. I'd applied Lucas assembly lube to faces of thrust washers, and it's pretty viscous, so that may have figured in.
After levering crank toward dial gauge, I see 0.002" If I maintain very light pressure with screwdriver (levering) I see 0.0025" - 0.003"

On the topic of rod orientation, the tech info I found online referring to "engine front" means pulley end of engine. i.e. the bump on rod and cap face towards the pulley. My Bentley Fox manual shows a clearer picture and I now
see that detail in the OP's pics. I realize this thread is about bearing replacement though.


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