Sculptor7

Trying to overhaul my granddaughter's old Trek 800 Mountain Bike. The bottom bracket obviously needs work because the crank shaft has a deal of play in it. It takes an Allen wrench to undo the bolt that holds the crankshaft on. After that I screwed in my Park crank removal tool and tried to get the crank to budge but no luck. I am a little afraid to put too much effort into turning the handle on the Park tool because I have read so much about the danger of stripping the aluminum threads on the crank. It is obviously a tapered crank and I believe I am doing everything correct. My Park tool has a handle that is at best 7 inches long. Do I need more leverage?

reptilezs

first inspect for any washers or obstructions. grab the correct puller. loosen the center driving plug and firmly tighten the puller body into the crank arm. 3-5 threads. turn the driver and off it comes,

jeepr

I have had a couple that the puller doesn't fit in correctly. Only with the type of cranks that have a bolt (as opposed to a nut.) I have a fairly old puller and the tip is pretty worn. I found that putting a small bolt into the center of the crank with a head that will pass through the hole in the crank, pushed the arm right off.

thook

If that doesn't work, definitely a pulley remover rented from an auto parts store will. Much more leverage and won't strip the threads. Just get the three arms that grab around behind the spider/arm real well. Worked for me. Threads were stripped. Bummer.

Oh yeah.........and, I used some rubber tips that normally are used for capping off vacuum ports on EFI vacuum rails. Use the smallest ones that'll fit. Keeps any marring of the crank from happening and better grip.

Okay, that's all......

1saxman

You're probably pushing against the spindle end and the crank arm at the same time or just hitting the crank arm because of the fitting problems mentioned above. Take another look at the driver you're using and the size of the spindle end you have to push against. You were right to stop before stripping out the crank arm threads, because that was going to happen next. Be advised that the Park tool has a double-ended driver which should fit most modern bikes. You unscrew it from the head of the tool, flip it and screw it back in. Maybe you're using the wrong end for your application.

Sculptor7

Well, as so often happens, this morning I took another look at things and decided I was doing everything right so I just applied a bit more force and sure enough the crank came off. Also have the by-product of learning a few things. Thanks for your replies. BTW it's as I suspected, a mess in there. Probably never been serviced.

Purp

Check the surfaces of the cups and cones, if they are severely pitted (not smooth) they may be beyond overhauling/repair, and need to be replaced. New square-taper BBs are dirt cheap.

w98seeng

I bought a new Shimano BB-UN26 sealed bottom bracket for $15. This is definitly the way to go. Just measure the spindle length you have now so you know what length BB to get. The only info I could get for a Trek 800 was for a 1999 (https://www.bikepedia.com/QuickBike/B...port&Type=bike) and it took a 122.5mm spindle and has a 68mm wide English BB shell.

Ian

Sculptor7

Thought I had closed the book on this thread but as it turned out there was another chapter. After I got the adjustable side crank off and inspected the bearings I saw they (the balls) were all completely falling out of the retainer. The cones looked not too bad so thought I would replace the bearings. However, unlike some of the vintage road bikes I have been overhauling the axle would not come out from the left or adjustable side. I then removed the drive crank (with little difficulty) and tried to take off the fixed cone(?). No luck. It was frozen solid and to make matters worse there appeared to be a total mess inside from the noise and play when I turned the crank.
My LBS would install a cartridge spindle for $40 if they can get it apart with not too much labor. If not it might cost $60. Since this bike is now a second bike (I gave my granddaughter a road bike I had overhauled) I have to see what she would like to do. Have not much incentive to waste any more time on it.

1saxman

'the Park tool has a double-ended driver which should fit most modern bikes. You unscrew it from the head of the tool, flip it and screw it back in.'

Oooops! This is wrong. The 'driver' is the threaded pin that is part of the tool. The only part that is 'double-ended' is the adapter that threads to the crank arm. Sorry about the misdirection.
BTW, the fixed cone may have LH threads - did you try turning it clockwise?

jeepr

The axle should come out the non-drive side. Sometimes there is a plastic sleeve between the bearings that gets stuck in place and stops the axle from pushing through. The fixed cup should come out by turning it clockwise. I have used a bolt through the bottom bracket with big washers to hold the tool on the fixed cup to get some decent leverage on it. They can be a real pain sometimes.

Sculptor7

Think I was turning the fixed side counterclockwise at first. This whole thing about threads on English, Italian,Japanese, etc. is a little confusing to me. Especially since it is an American bike with Japanese parts. The thing about the plastic sleeve is a possibility for not being able to remove the spindle from the non-drive side. Should have looked in there more carefully with a flashlight.