Does anyone know when Cat increased the crankshaft bearing sizes on the D8800 engine and if under size bearings are still available? Regards Andrew

Andrew as far as I know all of the 1H, 2H, and 9G engines were all the same with 50 under being available. Don't if any standard or undersize are available now. The journals on the number series precedeing these were smaller.

Hi Andrew,
as Dick says.
All my Lit. indicates that Std. B/E is 3.6240-3.6250" and the Mains Std. are 3.7490-3.7500" from D7 to early D7E, by my Federal Mogul chart some in between D7E's had 4.25" mains , seems later ones went back to the old dimension? Anyway your query is for D8800 so it is as given above for later engines.
Attached is part of the Federal mogul chart for 4cyl. 5 3/4" bore 4cyl. that I got from Head Hunters some time back.
Line 5B covers D7 from 3T,4T,6T,&7M.
Line 6A covers all RD7.
Note that 10-20-25-50 U/S were available from F/M.
Also note the crankshaft forging No's in this chart.
Also attached from a Cat chart are dimensions for earlier smaller shafts with S/No cut offs.
I put the extra in for future referance by others.
Cheers,
Eddie B.

Eddie, I am hving trouble with the F,M chart as the crank b.e size on my engine is 3.250 regards Andrew

My service manual (Form #5060-Diesel Engines- 1940) makes reference to Early 5-3/4 in. bore 3 & 4 cyl engines as having 3.500 in mains, later 4 & 6-cyl engines as having the 3.750 mains. It doesn't say by year or model number when things changed but I would guess early would be the RD series:confused:
Similar situation with the rods....3.250in. early and 3.625 in. late

Andrew,
here is the only other reference I have for crankshaft journal sizes, it is a 1941 edition of the Serviceman's Reference Book for Caterpillar Diesel Engines.
The sizes are recorded the same as before.
Maybe your shaft is an after market unit or has been built up above standard in the past or there is some confusion reading a non-standard under size on the journal.
I can only suggest checking the shaft forging part/number as per the Cat chart above and bearing P/No's for Cat numbers etc.
Failing that maybe try contacting H/H and see what John C. has to add.
With the limited lit. I have here, and after looking through old S/Mags etc, I am sorry it seems that I can not can not help any further.
Good luck,
Eddie B.

Sorry Eddie, ment 3.250", I was trying too find a latter bearing set to fit my RD rgards Andrew