Splitting The Crankcase On A 1996 670 [Archive] - Snowmobile World : Your #1 Snowmobile Forum

: Splitting The Crankcase On A 1996 670


96mach1
01-29-2007, 03:18 PM
I split the crankcase and found pretty much what I thought i'd find, one of the outside PTO Bearings came apart or more like exploded, It's the one on the inside of the 2 pto bearings....I have no idea what caused it, oil injection works plus I add a little of oil to the gas but the previous owner ran it hot when the base gasket let go out on the trail and I suspect that may have contributed to it, but anyway bearings are ordered and I am wondering how to get the old bearings off...do I heat them up and remove them with a puller?

And Thumbdoctor you mentioned in your post to use loctite 5910 for the gasket surfaces, so you mean do not use a gasket when putting the cases back together just use the loctite or use the loctite and gasket? The case halves had no gasket when I split them, I think I just answered my own question but I want to be sure and do it right

Thanks for all the help

Brian

skoal_mint
01-29-2007, 04:15 PM
not much that you can do...maybe put the cases in a varsol machine and clean them nice..

and you can always paint them too

heres a list of engine paint from duplicolor

DE 1601 Ford Blue
DE 1602 Universal White
DE 1604 Universal Gold
DE 1605 Ford Red
DE 1606 Ford Dark Blue
DE 1607 Chevrolet Orange-Red
DE 1608 General Motors Blue
DE 1609 Chevrolet Blue
DE 1610 Pontiac Blue
DE 1611 New Ford Gray
DE 1612 Gray Engine Primer
DE 1613 Gloss Black
DE 1614 Cummins Diesel Gold
DE 1615 Aluminum
DE 1616 Pontiac Blue Metallic
DE 1617 Ford Green
DE 1618 Detroit Diesel Alpine Green
DE 1619 Chrysler Green
DE 1620 Chevrolet Orange
DE 1621 Old Ford Blue
DE 1622 Chrysler Orange
DE 1631 Chrysler Corp. Blue
DE 1632 Chrysler Industrial Red
DE 1634 GM/Chrysler Low Gloss Black
DE 1635 Ford Semi-Gloss Black
DE 1636 Clear
DE 1638 Cummins Beige
DE 1640 Plum Purple
DE 1641 Grabber Green (Lime)
DE 1642 Daytona Yellow
DE 1643 Torque ‘N’ Teal
DE 1644 Racing Green (Hunter)
DE 1645 Ruby Red
DE 1646 Trophy Blue
DE 1650 Cast Coat Aluminum
DE 1651 Cast Coat Iron

Thumbdoctor
01-29-2007, 08:35 PM
Heat up your flywheel hub with a heat gun before using a puller (has loctite 271 on the taper) Never hit the puller with a hammer !!!. Clean your cases with aluminum brightener (sold at truck washes for aluminum trailers) always rinse aluminum parts with cold water and blow dry. Make sure any solvent you use completely evaporates and doesn't contaminate the case half sealant. BRP bulletin states using Loctite 5910 sealant for the case half's. The best way to apply said sealant is to get yourself a rubber ink roller (available at most art stores) and squeeze some sealant onto a piece of glass or plastic the roll it out then roll it onto both gasket surfaces of the cases. This way, no excess sealer will find its way into the engine. Get your replacement PTO bearings from a crank re builder. The bearing races on OEM rotax (Fag) bearings have cheap plastic ball retainers which tend to melt when your clutch heats up (read overheats). Adrien Bernard (http://www.atelieradrienbernard.com/contenu/index_ang.cfm)engine re builders sell steel caged bearings at about 1/2 the price of Rotax stock.Clean the PTO stub with 180 silicon carbide sand paper befor installing the new PTO bearings. Warm the bearings to 200 degrees F and drop them on. Don't drive them on. Be very gentle with the old center seals make sure you clean them and orient them exactly as they came out. Replace the PTO and MAG seals with OEM Rotax (ceramic impregnated wipers) units as they are a lot better than jobber. Apply a little Lithium grease to the seal lips. Chase all crankcase threads with a tap to clean out dirt and sealant. Apply a little grease under the bolt heads befor you torque them down. Follow these step and you'll enjoy a bullet proof build.

Good Luck !!!

96mach1
02-01-2007, 08:09 PM
tt

labudda
02-01-2007, 08:20 PM
tt[/b]

why are you ttt ing when you are not updating from the information provided?

96mach1
02-01-2007, 08:33 PM
I did update , just edited my first post

Thumbdoctor
02-01-2007, 08:44 PM
I split the crankcase and found pretty much what I thought i'd find, one of the outside PTO Bearings came apart or more like exploded, It's the one on the inside of the 2 pto bearings....I have no idea what caused it, oil injection works plus I add a little of oil to the gas but the previous owner ran it hot when the base gasket let go out on the trail and I suspect that may have contributed to it, but anyway bearings are ordered and I am wondering how to get the old bearings off...do I heat them up and remove them with a puller?

Generally the cause of PTO bearing failure is heat, the bearing is being side loaded by the CVT, belt friction and combustion heat. The fact that the base gasket failed would cause that side to operate leaner and that also contributes to heat. Some ill designed clutch kits also increase the running temperature of the driven clutch thus adding stress on the bearings. Do not heat the bearings to get them off. The best way to get the 2 PTO bearings off is to employ a bearing splitter with a double jawed puller attached to it. The inside bearing is very tight to the crankshaft counter weight so care is required. you need to orient the bearings in the same position as they came out so that the locking pins fit into the case recess. If you don't have either of these tools, I would recommend taking the crank to a BRP dealer and have then do it. The new bearings need to be installed in a correctly spaced fashion otherwise they won't seat in the cases properly. Yes you answered your own question, there is no gasket for the crank case halves just Loctite sealer.

And Thumbdoctor you mentioned in your post to use loctite 5910 for the gasket surfaces, so you mean do not use a gasket when putting the cases back together just use the loctite or use the loctite and gasket? The case halves had no gasket when I split them, I think I just answered my own question but I want to be sure and do it right

Thanks for all the help

Brian[/b]

labudda
02-01-2007, 08:57 PM
I did update , just edited my first post[/b]

sorry I dont usually reread. just go to the newest post and see what the new conditions are.

96mach1
02-01-2007, 09:28 PM
sorry I dont usually reread. just go to the newest post and see what the new conditions are.[/b]

Not a problem, I should have just added a reply but figured I'd save space and edit

trailblazer
02-03-2007, 11:15 PM
not much that you can do...maybe put the cases in a varsol machine and clean them nice..

and you can always paint them too

heres a list of engine paint from duplicolor

DE 1601 Ford Blue
DE 1602 Universal White
DE 1604 Universal Gold
DE 1605 Ford Red
DE 1606 Ford Dark Blue
DE 1607 Chevrolet Orange-Red
DE 1608 General Motors Blue
DE 1609 Chevrolet Blue
DE 1610 Pontiac Blue
DE 1611 New Ford Gray
DE 1612 Gray Engine Primer
DE 1613 Gloss Black
DE 1614 Cummins Diesel Gold
DE 1615 Aluminum
DE 1616 Pontiac Blue Metallic
DE 1617 Ford Green
DE 1618 Detroit Diesel Alpine Green
DE 1619 Chrysler Green
DE 1620 Chevrolet Orange
DE 1621 Old Ford Blue
DE 1622 Chrysler Orange
DE 1631 Chrysler Corp. Blue
DE 1632 Chrysler Industrial Red
DE 1634 GM/Chrysler Low Gloss Black
DE 1635 Ford Semi-Gloss Black
DE 1636 Clear
DE 1638 Cummins Beige
DE 1640 Plum Purple
DE 1641 Grabber Green (Lime)
DE 1642 Daytona Yellow
DE 1643 Torque N Teal
DE 1644 Racing Green (Hunter)
DE 1645 Ruby Red
DE 1646 Trophy Blue
DE 1650 Cast Coat Aluminum
DE 1651 Cast Coat Iron[/b]

So does this answer have something to do with answering something asked before you edited your original post? If not, am I missing something?

Confused

Jeff

Thumbdoctor
02-04-2007, 08:02 AM
So does this answer have something to do with answering something asked before you edited your original post? If not, am I missing something?

Confused

Jeff[/b]

Me too Jeff is this an add for a paint manufacture. Certainly not a great upgrade.

96mach1
02-04-2007, 10:24 AM
Nahh I just asked what to watch out for or what is a good to do when splitting the case...Nothing about paint, the head is purple...enough color for me. Anyway I had to send out the crank because the pto side crank counterweight had opened up leaving too much connecting rod thrust and allowing the counterweight to rub on the case which trashed both pto bearings...but it was never overheated...HAHAHA
The cases are cleaned up and im in the process of cleaning up the ports...mild porting and case matching to the heads while im waiting for the spi pistons then the heads are going .020 over, then its all back together and hope it runs!

Anyone have any good case porting pictures on the 670? I searched and found a few threads but most were from like 2003-4 and the images werent available

Brian