9 replies to this topic

[andrewoc42]

Hey all,

 

So I'm about to begin the rebuild of my TDM 850 4tx engine. I've just ordered and awaiting a block and top end casing for my engine as the old has a crack in it.

I'm wanting to replace all bearings and gaskets obviously for best practice.

​Does anybody have a complete bearing list in what i'll need to do so? I cant find the specifications in the service manual I have, which is obviously no help and I don't want to get the wrong ones! Is there a kit available, or where would be the best location to obtain them?

​Could anybody recommend me a reputable gasket kit also? I'd rather get it right the first time.

 

Thanks in advance,

 

Andrew

[Studley Ramrod]

Hi Andrew, welcome to the club.   In short, errrr no.  Don't think anyone has put up a list of all the bearing sizes etc.  I rebuilt a mk2a engine and did a blog about it, see my sig below, Studleys Mk2a bloggerydoodaah.  Amidst the blog there's a post where I listed the items I'd purchased and who I'd got them from.

http://www.carpe-tdm...6&showentry=121

 

I strongly recommend you using an oem head gasket, I tried a Wemoto head gasket and it leaked like fook.  Others have bought and used engine gasket sets such as those by Athena, or made their own using gasket paper, but I bought the gaskets seperately from Fowlers and Wemoto.  Fowlers is also handy for seeing what you need using the parts fiches.

https://www.fowlersp...blue-metallic-c

You might even be able to work out which bearings you'll need.  I didn't need to replace any bearings. I used both the Haynes manual and the Yamaha service manual to help me along. 

You'll need a few special tools like a clutch basket holder, rotor puller, decent torque wrenches and the like.

I didn't need to look into the crank bearings/shells but you might need to either use plastigauge and work out what shells you need, or whip it into a decent auto-engineering place and get them to measure them, and provide you with what you need.

[fixitsan]

For big end bearings you need to note the numbers stamped on the side of the big ends....and cross reference them with a code stamped on the crank webbing..... these are clearance values and the combination of the two tells you which of the available sized big end shells to get...... a similar process should be followed for the crank main journals as far as i can remember.

So you'll need to download a service manual (plenty of free ones about). I did this on my mk1 a few months ago....it's not too difficult

[TYREDNGRUMPEE]

Treat that heavy crankshaft as if made of porcelain.

Do all your work on it when it is sat in one casing or the other.

If it is out of the cases, lay it gently on a deeply folded blanket.

The slightest bump / knock, risks causing a fault that will only become apparent 1000 miles later.

Ever seen a crankshaft shatter into 4 pieces? It is a bugger.

[James]

When you get around to buying the bearings you might want to check out Simply Bearings in Leigh (Google 'em). I replaced every bearing in my XL600R engine rebuild, saved over 75% on Honda prices while still having top quality bearings.

[andrewoc42]

Thanks for all of the help guys, greatly appreciated.

I'm going to try and source all of the parts locally as I'm in Australia, and don't want to wait weeks upon weeks for shipping. However them sites supplied definitely help with what I require.

 

It's my first engine rebuild, so i'm sure I'll be asking alot of questions So any tips and or tricks would be greatly appreciated!. Yet to rip the current engine out as I'm waiting on the replacement parts. However looking forward to getting it up and running.

Are there any other common problems with these engines which I should be looking at and possibly be replacing during the rebuild? Obviously cylinder and valves may need to be replaced, however I'd like to replace anything now that may be problematic before I have to do it all over again in 1000km!!

 

Thankyou

 

Andrew

[fixitsan]

Check the piston rings too Andrew. Worn rings can lead ti high oil consumption......and check that the cylinder bores are round and not oval.

Once you have the cases apart you can get straight into the gearbox, all the gears are on two shafts....check for worn selector dogs.. ...as well as checking endfloat (controlled by shims)



Photograph everything where there could be confusion during reassembly

Every bolt hole underneath the engine is numbered 1 to 20 (or thereabouts)....get a sheet of cardboard and punch small holes in it, number them up and push the bolts into their respective holes.

A few of the bolts holding the upper and lower cases togethee around the crank look identical but a couple are a few mm shorter...if you put them back incorrectly you end up with a bolt trapping a balancer shaft and a tight engine (ooops !)

[MickC]

As Studley said use a genuine head gasket I didnt and just before a scotland trip the  Head Gasket went.

If you are simply replacing shell bearings size for size that is stamped on the rear of the crankcase on the outside (actually more hand marked) the shells themselves are colour coded along the side of the shell Green--Brown and something else (just rub the side clean).

[andrewoc42]

Thanks for all of the help guys, I found a parts catalogue online, with that and all the help from you I now know what I need!
Much appreciated, I'm sure I'll ask many questions as my parts start to arrive!
Cheers, Andy

[fixitsan]

Thanks for all of the help guys, I found a parts catalogue online, with that and all the help from you I now know what I need!
Much appreciated, I'm sure I'll ask many questions as my parts start to arrive!
Cheers, Andy

 

 

The only stupid question is the one you don't ask.....