Thread: 300TDI Big end bearings..... Ohh the Humainity

These are the big ends and mains out of my 200 with 250k on the clock.
Replaced while doing crank, the only hic up I had was I put the cap on #1 bum about it took a few seconds to work out and no was damage done.
Can bearings be repaced engine in on a 300 ???

yep, same procedure as for the 2.25 5 mains engine but by the time you faf around getting the front dismantled in bay its almost quicker and IMHO certainly easier to pull the engine out and put it on a dedicated stand. it also lets you eyeball the clutch and gearbox input side of business which are plusses in my book.

The drawback to an engine out repair as opposed to engine in is you may loose the aircon gas which on occasion has been known to raise some questions as to about why you had it all disconnected...

Originally Posted by DEFENDERZOOK

hey clarkie.....did you do the work with the engine in or out of the car.....?

Engine in, jacked up the body and placed it on axle stands....
Working around the Diff is a sod...

.... and i guess you have to drop the crank - howdo you go with timing gear and the whole driveplate assembly? - oh and im up to 298000 km

Mick

simply back off the timing belt idler and ease the crank main journal caps down. it will hang enough so that if you remove the caps one at a time you can rotate the shells out... insert the new bearings and then repeat, when youve got all 5 in you go on to do you bearing compression checks.

The sod is you can only do the nip check on the mains as opposed to the bearing back contact test as well. (another reason I swear on removing the engine if you have the ability to do so)

On a low compression petrol Id be happy with just a nip check but any thing high compression (say over 10:1) or that will likely rev past say 5k rpm I prefer to make sure the bearings are actually making correct contact.

To do the Mains in a 200 or 300 would not be easy with engine in, BUT as the mains wear the bottom shells b4 the top (due to piston forces) if you were a cheap arrrrssssse bugger you could just replace the lower shells, but nuber 5 is not possible without disturbing the rear main.

But the Big ends which wear at a far greater pace are easy to do in place. just drop the crank and drop the 4 caps and then slide the old ones out and the new ones in. Dont mark the crank.

theres no need to drop the crank...

rotate the crank to bdc (for the cyl your about to do) or just a little past to make access to one side slightly easier.

unbolt the big end bearing cap, by hand push the piston up (after having removed the glow plugs or injectors)

slide the bearing shell out of the top end of the con rod

slide in the new bearing shell ,

mate up the big end bearing cap (after replacing the bearing shell)

turn crank to TDC by hand (pushing on the big end you havent just worked on is best) and then tighten the bolts to the first of the torque up values (gotta do that in 3 steps remember?)

repeat for all cyls then rotate to BDC to finalise the torque settings on all cyls.