lower crankcase

[paul61]

Hi been a reader of the forum for quite some time now ,and a trx owner for the last 5 years which after various other bikes(jota,900 Honda, gpx 750 and lastly 1100 gsxr) is a cracking bike for todays roads and certainly quick enough for a 50 something year old. All the time I have owned the bike it has had an annoying tiny oil leak from the lower crankcase on the oil pump housing. My question is it possible/ fairly easy to change the bottom half of the crankcase without stripping the whole motor, thanks in advance
Paul

[misterdimwiddy]

Hi Paul

I may be wrong but I doubt you could change the lower crankcase without stripping the motor completely.

I removed the balance shafts when I stripped my own motor and splitting the cases with these in place would be tricky when it comes to realigning with the crank during reassembly. Also main bearing shells may be differently colour coded depending on the numbers stamped on the crankcase and these would have to be paired obviously.

Getting the balance shaft retaining plates out requires the generator rotor to come off and this is quite a challenge in itself.

My thinking has always been that crankcase castings are used as a pair and if you damage one you have to change both.

Depending on the location of the oil leak in the pump housing can't this be resolved more simply?

Where exactly is the leak, how bad is it and has the lower casting been damaged to cause the leak? THere shouldn't be that much oil sloshing arouind in there at that level with a dry sump.

I have used plain old Araldite successfully on cracked engine casings before now. There are probably better liquid metal type epoxy products around.

Give us a bit more detailed info and someone on here may well have a soultion to the problem.

MrD

I had 3 different CB900F's back in my youth; loved em all especially the 998 RSC motor that I had in one.

[fung]

well......not completely worthless but it will help the spatially handicapped in diagnosing your trx's ailments

[Rod.s]

Hi been a reader of the forum for quite some time now ,and a trx owner for the last 5 years which after various other bikes(jota,900 Honda, gpx 750 and lastly 1100 gsxr) is a cracking bike for todays roads and certainly quick enough for a 50 something year old. All the time I have owned the bike it has had an annoying tiny oil leak from the lower crankcase on the oil pump housing. My question is it possible/ fairly easy to change the bottom half of the crankcase without stripping the whole motor, thanks in advance
Paul

Is the crack, where one of the bolts go into the lower case?

[paul61]

Hi guys
Thanks for the replies, the damage has been caused by a crash of some sort(not me), and the area has been repaired with some type of araldite or similar substance and appears to leak around the edge of this material its only a minor drip but I would like to try and seal it, my thoughts were to either grind this resin out and start again or change the casing which to be honest I wasn't expecting this to be an easy repair, because as suggested these are usually a matched pair and are probably line bored for the bearings etc.
The damage is the crankcase housing the oil pump sits in and not the external cover, I'll strip it down at the weekend and try to put some pictures on here (that could be a challenge damn computers!)

Kind regards
Paul

[alextrx850]

Where are you Paul, best advice is to add your location to your avatar box as we might have someone nearby to you give you a hand.
This is a GLOBAL forum...hope it goes well.