Triumph Rat Motorcycle Forums banner

1 - 17 of 17 Posts

·
Registered
Joined
·
2,905 Posts
Discussion Starter #1
It appears that i will need to replace the bushes and bobbins in my 1970 T120R swing arm -- looking for advice on removal and replacement of the bushes -- what is the likelyhood that the new bushes are "pre sized"
 

·
Registered
Joined
·
5,833 Posts
The Factory Service Manual in the General Data area states that they are pre-sized. While there is some figures given nothing to do with clearances is shown.


Removal of the bushes was the only job I didn't do on my bike. After I saw what was done I did all other work myself.
The shop manual covers the removal /refitting process. One thing I do when refitting bushes is place the bush in the freezer for a bit. In this case I would use a heat source to warm area the bushes are to be inserted into. It does make a difference in the fitting. (next time you want to get the rivets off the timing cover heat it in the oven to about 120/140 f )


If you do not have a factory manual they can be seen on-line


K
 

·
Registered
Joined
·
2,905 Posts
Discussion Starter #3
Thanks k -- i missed the info in the factory manual -- was expecting a large piece of detail - so nothing special - just knock em out and knock em back in ! -- was thinking of the heating / cooling ploy - luckily the swing arm is yet to get painted / powder coated -- good idea on the timing cover rivets ; always done it cold , so will try some heat
 

·
Registered
Joined
·
5,833 Posts
I would wait to do the bushings until after the arm is painted or coated. As far as the heating I would not want to get it hot enough to damage powder coat or paint wait till the Mrs. is out and use her hair dryer. On the reinstall I prefer to press rather than knock them in.


You do not need a lot of heat when you are dealing with dissimilar metals. You just need to be quick. If the Mrs. comes home and finds parts in her stove or using her hair dryer you WILL feel lots of heat..


K
 

·
Registered
Joined
·
15 Posts
Yesterday I removed my bushings, after trying several different ways unsuccessfully, I tried using a socket wrench with an OD the same size as the bushing with a 1/2” drive with extension, by holding one side and the other, I was able to hit with great force and I was able to remove the bushing. On the second side, I went with a larger socket which contacted the bushing 360 degrees and again used great force to remove.
 

·
Registered
Joined
·
248 Posts
Hi Wol,
I know nothing of the t120 swing arm bush set up, so apologies in advance if this is non relevant.
The t140 bushes you buy now days need to be line reamed for sure, so it will be of interest to see if the T120's need to be.
I was real lucky in finding on flea bay the service tool for a 10er which made removing and installing so simple, as per in the fore of the pic. Again, I don't know the set up of a T120, but if vaguely similar, a tool like this could be made up.......

Col
 

Attachments

·
Registered
Joined
·
34 Posts
I would wait to do the bushings until after the arm is painted or coated.
K
Can I disagree with you?

I confess I wasn’t planning to change those bushings, I just sent the whole frame for painting. The mechanic I use was professional enough to check my parts and recommended I do this job as part of painting the frame. He told me the bushings needed to be changed BEFORE painting, as there is a great chance you will ruin the paint. He explained these need to be reamed to size by a machine shop. Same with the camshaft bushings. The machine shop charged me about $60 to do the job, plus parts. Not the cheapest solution but at least I know it was done better that what I could have done on my own.

Just my 2c.
 

·
Registered
Joined
·
5,833 Posts
Can I disagree with you?

I confess I wasn’t planning to change those bushings, I just sent the whole frame for painting. The mechanic I use was professional enough to check my parts and recommended I do this job as part of painting the frame. He told me the bushings needed to be changed BEFORE painting, as there is a great chance you will ruin the paint. He explained these need to be reamed to size by a machine shop. Same with the camshaft bushings. The machine shop charged me about $60 to do the job, plus parts. Not the cheapest solution but at least I know it was done better that what I could have done on my own.

Just my 2c.
My friend you are welcome to disagree with anything I or anyone else out here says..... just be sure you have your ducks in a row.

On the camshaft bushings YES these need to be reamed. The tool is not cheap. As far as what you were charged I do not know the labor rate in your area and you know your limitations. I would agree with having the frame on am OIF bike painted with the rest of the bits being powered coated. I remember working on one bike, done by a well known shop, that had a large bad spot on the powdered coated frame.

Of your mechanic you and I have differing opinions.

1 Why are you having Pre-Sized Bushings reamed?

2 These bushings are a press fit not Hammer fit, He thinks they were fitted at the Factory PRIOR to finishing the Swing Arm?

3 As far as I know all 650/750 twin/750triples swing arm bushings from 1963 were pre sized

4 What do you think was reamed?


K
 

·
Registered
Joined
·
248 Posts
Can only comment on my 76 V and another 77 V ( Rod's) that I've recently done and helped with,
Both had to be line reamed.
I rang 1/2 a dozen suppliers after the fact, thinking I had drawn the short straw, and was informed that they no longer come
sized and must be line reamed.
I cannot comment on models pryor, but it seems that this is now the case.
The guy that did it for me, said he's been line reaming customers triumph swing arm bushes for many a year.
I managed, with the proper tool, to extract, re fit, wrap the swing arm for the reaming to be out sourced, without getting as much as a scratch on my fresh paint work.
Sure would have made the jobs a whole heap less stress full if they were pre sized, but alas, not any more.

Col
 

·
Registered
Joined
·
2,905 Posts
Discussion Starter #11
just replaced the bushes in the swing arm - i used a long 1/2 drive socket extension as a drift - i ground the "female" end square to the shaft to get a sharp edge that would catch against the slight lip of the old bush - took some beating to get them out ! - i polished a very slight taper onto each side of the swing arm bearing housing to help location and starting the new bushes - used a piece of 10mm threaded rod and some large thick washers to wind the new bushes into place ( assembled both bushes onto the threaded rod so both could be fitted in a single assembly of my "tool" - intially it needed a light tap to get the bushes lined up once some tension was on the nuts - then no problems - just wound the nuts untill the bushes were flush with the swing arm - they cannot go in too far as there is a slight lip inside - offered up the new bobbins and they fitted perfectly -- so they are indeed pre- sized - at least the ones i used are - (came from Harris)
 

·
Registered
Joined
·
34 Posts
My friend you are welcome to disagree with anything I or anyone else out here says..... just be sure you have your ducks in a row.
You are right, my ducks could be in total disarray :smile2:

What I got back from my mechanic was a swing arm with a copper colored bushing. They had some grooves inside that I figured were to help with the greasing. Those bushings looked like they had been reamed to the swing arm. What I understood is those bushings needed to be inserted (pre-size , reamed, hammered, etc.…) prior to the painting, otherwise the process of inserting the bushing could damage the paint. Not sure if that’s how they did in Meriden but that is how my guy does it. Might be worth mentioning that my frame was not powder coated, it was painted, which might be more prone to damage from inserting things. There might be more than one right way to skin this cow, I believe
 

·
Registered
Joined
·
5,833 Posts
You are right, my ducks could be in total disarray :smile2:

What I got back from my mechanic was a swing arm with a copper colored bushing. They had some grooves inside that I figured were to help with the greasing. Those bushings looked like they had been reamed to the swing arm. What I understood is those bushings needed to be inserted (pre-size , reamed, hammered, etc.…) prior to the painting, otherwise the process of inserting the bushing could damage the paint. Not sure if that’s how they did in Meriden but that is how my guy does it. Might be worth mentioning that my frame was not powder coated, it was painted, which might be more prone to damage from inserting things. There might be more than one right way to skin this cow, I believe


Well if the ducks are in a row how are the Canadian Geese doing ?


Skinning a cow is udder nonsense....


For those of you that are buying 82 6042 or 83 2521 that require reaming I suggest you find a new supplier. I talked to my Wholesale Supplier today he said the ones I get from him do not require reaming.
500 bushings 82 4076 do require reaming


As far a damaging a painted /powder coated swing arm might I refer you to Wol's post.


ANYONE that hammers the swing arm bushings in is a BUTCHER.


K
 

·
Premium Member
Joined
·
228 Posts
I replaced the swing-arm bushes on my '69 T120R in 2013 using exactly the instructions given in the workshop manual. No reaming, no press, no sweat. Must be pretty easy to do if I didn't have any problems.
 

·
Registered
Joined
·
5,833 Posts
I replaced the swing-arm bushes on my '69 T120R in 2013 using exactly the instructions given in the workshop manual. No reaming, no press, no sweat. Must be pretty easy to do if I didn't have any problems.
Yup these bikes aren't rocket science.


Your pages are interesting.


K
 

·
Registered
Joined
·
34 Posts
I replaced the swing-arm bushes on my '69 T120R in 2013 using exactly the instructions given in the workshop manual. No reaming, no press, no sweat. Must be pretty easy to do if I didn't have any problems.
Indeed, your pages are VERY interesting. Probably the best of its kind as far as I know.

Congratulations!!
 

·
Registered
Joined
·
1,131 Posts
Well, you will find that the current crop of Tawian bushings will often need to be sized after installing.

If you look at the bearing you will see it is split. Use the split to remove the old bearing using a cape chisel to collapse the bearing shell in on itself. Done with some care you will not leave any marks on bore in the swing arm. Then the bearing shell falls out.

The factory tool is an aluminum bar about 3" long turned down so that it has a shoulder. The part that extends into the bearing is about .005" smaller than the i.d. of the new bearing. Then they are installed tapping the tool with a hammer. No heat or cooling required. If you need heat you are doing it wrong like having the installing tool cocked.

If you want to be real clever make up a plug that is a slip fit in the swing arm. Turn down one end so that you can slip the bushing on the tool with about .005" clearance (on the new bearing). Then slip the large end into the swing arm to keep the bearing square as you offer it. If I was going to use a press this is what I would do.

Any time you offer something like this use very light blows, or just a very light press and release, until you confirm the part is square to the hole. Then just tap it in. If things aren't square it will take more force, you can distort the split bushing and you will not have a satisfactory outcome!!!! We covered all this in Vintage Bike some 20 years ago.

It isn't any easier, or are you going to get a better outcome, using a press. No matter how you do the job the key is keeping the bearing square with the hole through the entire process. That's the trick, not whether you press or hammer, cold or hot.
John

The 500 swing arm is a bit trickier to do. I always leave one bushing in the swing arm while I replace and ream the first bushing. I use the old bushing as a guide to get the first one right. Then I remove the other bushing and use the new one as reference to line bore the second bushing. I have found that it gives you a much better outcome than removing both and trying to line ream the bushings and keep them square to the swing arm.
 
1 - 17 of 17 Posts
Top