Moderator DirtyDT Posted September 12, 2011 Moderator Posted September 12, 2011 I am going to use some heat and plusgas before trying to remove the rest of the cylinder studs from a crankcase. I have never had to heat ali before so can I have some advice please? My questions are; Heat gun or blow torch? Heat the stud or the crankcase? How hot? Any gun/torch recommendations/techniques? The case is ali and I dont want to melt the casing. If all goes well I may also try to get the blind bearing out by the heat and slam dunk method. Ta.
neversaydie Posted September 12, 2011 Posted September 12, 2011 Try to keep well clear of the ali. Try almost red heating a nut with the same thread then screw that on with a socket and let the heat transfer through to the stud. That keeps the flame well away. Thing is to be very patient, keep trying the stud both ways, dont give up at the first attempt
Moderator Airhead Posted September 12, 2011 Moderator Posted September 12, 2011 in complete contradiction to what neversaydie, said use a gas blowlamp on the case around the threaded area, the ally will expand quicker than the stud, possibly spray the stud with penetrating oil briefly to cool it and hopefully get some in. If it cracks free and then jams dont force it but work it both ways, gradually the arc of movement will become more and more until it unscrews without fuss Plenty of penetrating oil is the order of the day
Moderator DirtyDT Posted September 12, 2011 Author Moderator Posted September 12, 2011 Thanks for the replies. I will have a go at the weekend. Can I heat more than once?
Moderator Airhead Posted September 12, 2011 Moderator Posted September 12, 2011 yes but no need, get the mrs to play the heat while you do the rocking and spraying.
Moderator DirtyDT Posted September 12, 2011 Author Moderator Posted September 12, 2011 Er..............I will buy a different bike Just plusgassed the rest and will do it ove the week and then the week and plussgas.
Moderator Cynic Posted September 12, 2011 Moderator Posted September 12, 2011 Just an extra 2 peneth on the blow torch/heat gun option. A heat gun cannot heat the ali far enough to cause a problem no mater what setting etc and its constant.. Blow torch on the other hand......
Moderator drewpy Posted September 12, 2011 Moderator Posted September 12, 2011 dirty, do you wan to borrow my stud extractor?
Moderator DirtyDT Posted September 12, 2011 Author Moderator Posted September 12, 2011 Cynic - Oh yes a blow torch. Boy are they expensive for what they are. Would a box of matches do? Drewps - Thanks for the offer of the loan. I have a Halfords Professional set of stud extractors which seem OK to do most things, well with the 600mm breaker bar attached Like these LINKY but part of the professional range. Have you a different one or a recommendation ta? I will also need a blind bearing puller, looked at a couple which use hooks but there is no gap under this bearing. Bummer!! Mind you I do love tools.
Moderator Airhead Posted September 12, 2011 Moderator Posted September 12, 2011 ....I will also need a blind bearing puller, looked at a couple which use hooks but there is no gap under this bearing. Bummer!! Mind you I do love tools. when i did my DTMX i found a blind needle roller bearing, needless to say i didnt change that one!
Moderator DirtyDT Posted September 12, 2011 Author Moderator Posted September 12, 2011 when i did my DTMX i found a blind needle roller bearing, needless to say i didnt change that one! Yep. This is on a tranny shaft. I do have to knock out a needle bearing but it is not blind. I just wanted to make sure that the bearings were still available before I beat it out.
yamahait Posted September 12, 2011 Posted September 12, 2011 hi id go for the blow lamp on ali around stud,shouldnt need to be massively hot to move stud,as for blind bearing,same again,heat outside of casing around bearing,keep moving blow lamp around to get even spread of heat,when hot a good tap with a mallet should dislodge it,i have done this with an oxy acetelyne torch and never melted casings,just keep moving flame it will be o.k.
Moderator DirtyDT Posted September 12, 2011 Author Moderator Posted September 12, 2011 Cheers yamahait. I have read about blind bearing removals like this. Another suggestion is to fill the bearing space with grease or soggy tissue and then knock a shaft into the bearing hole and pneumatic pressure pushes the bearing out. Luckily the Taxman sent me a cheque on Saturday for £223 that he owed me from 2008.
Moderator drewpy Posted September 12, 2011 Moderator Posted September 12, 2011 Cynic - Oh yes a blow torch. Boy are they expensive for what they are. Would a box of matches do? Drewps - Thanks for the offer of the loan. I have a Halfords Professional set of stud extractors which seem OK to do most things, well with the 600mm breaker bar attached Like these LINKY but part of the professional range. Have you a different one or a recommendation ta? I will also need a blind bearing puller, looked at a couple which use hooks but there is no gap under this bearing. Bummer!! Mind you I do love tools. mines a bit like this can you not use an expanding rawl bolt to grip inside the bearing, then slide hammer it out?
Moderator DirtyDT Posted September 13, 2011 Author Moderator Posted September 13, 2011 I have seen that type of extractor. I might get one. I did think about a rawlbolt. at the moment the bearing is sitting in a bath of plusgas
Moderator Cynic Posted September 13, 2011 Moderator Posted September 13, 2011 I have seen that type of extractor. I might get one. I did think about a rawlbolt. at the moment the bearing is sitting in a bath of plusgas Again, heat. Even money you heat the case with a heat gun and leave the shaft in the bearing (after chilling it in the fridge helps too) to keep it cool and it may fall out of the case, not joking! A heat gun is an engine builders best friend. When i rebuilt my DT motor i used the fridge/heat method and the bearings litterally rattled with the clearance they had till they heated up.
Moderator DirtyDT Posted September 13, 2011 Author Moderator Posted September 13, 2011 Cheers Cynic. I will pick up a heat gun during the week. I was going to use the hot/cold method of getting the bearings back in but did intend to put the casings in the oven (and bearings in the freezer). I will try the heat gin for that as well now. A bit of a way off thinking of bearing fitting, Need to clean and spray first. I will also try the heat for the blind bearing and then the rawlbolt.
Moderator drewpy Posted September 13, 2011 Moderator Posted September 13, 2011 I have seen that type of extractor. I might get one. I did think about a rawlbolt. at the moment the bearing is sitting in a bath of plusgas the best bit about those ones is you can get close to the case so less twisting of the studs to absorb the energy!
Recommended Posts