1979 RM FORKS

[RM Ted]

OK WHATS THE TRICK IN PULLING APART 79 RM N FORKS (38MM)
GOT A SET THAT NEEDS NEW SEALS BUT STUFFED IF I KNOW
HOW TO GET THEM APART.THEY ARE TOTALLY DIFFERENT TO MY
RM C FORKS.I MADE A TOOL TO GET THEM APART,WHICH MADE IT QUITE EASY.
BUT ITS NO USE WITH THESE.ANY IDEAS??

[crs-and-rms]

i think its a 24 mm hex that you need to hold the damping rod

[crs-and-rms]

or it could be a round top 14 mm with two sides flatend to 12 mm ,  a quick way of making one  use some 20 mm square tube put it in vice and flatend it till its 12 mm in side dia then use shifting spanner on tube to undo damping rod

[pokey]

.I MADE A TOOL TO GET THEM APART,WHICH MADE IT QUITE EASY.
BUT ITS NO USE WITH THESE.ANY IDEAS??

 so the rod is loose but still wont seperate?

 see The Doctors topic on the same. soak in CRC or something for days then apply brute force.

[RM Ted]

THE BOLT SEEMS TOBE WRIGHT AT THE BOTTOM OF THE FORK LEG.CAN'T REALLY SEE IT,IM WONDERING IF THEY ARE N FORKS??THE DAMPNING ROD IS ONLY THIN.NOT LIKE THE C MODELS,WHERE YOU CAN GET TO IT ON TOP OF THE FORK LEG.

[Doc]

Clarkey so long as the allen screw under is totally removed and the circlip above the seal is removed also then it's just a matter of persistently yanking them apart like a slide hammer. Seems crude but this is the method. It's recommended the split slipper ring on the lower end of the inner should be replaced also.

[oldmotoxer]

Hi Clarkey, I have a 79 RM400 which I have replaced the fork seals in so try the following. As you probably know there is an Alan head cap bolt in the bottom of the outter/lower fork tube. Using an air impact gun fitted with the correct size alan head socket hold the inner/upper fork tube and try to crack the bolt loose with short bursts on the air impact gun. If you have already loosend the alan headed cap bolt with an alan key or some other then your screwed  and you will have to resort to finding something to hold the hex type section that this alan headed cap bolt engages down the inner/upper fork tube. You will need a very long 3/8" drive extension fitted with the correct size socket but try the fisrt steps on the loose bolt anyway, you maybe lucky 

[brent j]

I'm pretty sure the RM forks are much the same as early 80's PE175.

I found the following things helped getting them apart. But both rely on an impact wrench..........

Turn the fork leg upside down and lean on the lower leg with all your body weight (spring must be fitted).
Use an impact wrench to undo the allen bolt. Take care of the air fitting in the fork cap, I found my weight on the spring will hold the damper rod in place until the allen screw comes out.

OR

Jam a broom stick into the top of the damper rod (spring removed) use the rattle gun.

I'll measure the multi hex on one of my spare damper rods tomorrow night and try to work out a bolt size to use to anchor damper rods if the above won't work.

Cheers

Brent

[Graeme M]

The easiest way to get the tension on leading axle forks is to leave the fork in the triples and use a tiedown between bars and an axle through the axle clamp. Then you can tension that fork up as tight as you like. I've never even needed to resort to the rattle gun doing that...

[Viper79]

I made up a tool that does the trick just fine.  I used a piece of 3/4" water pipe 60 cm long and welded a 24 mm head bolt into the end of it.
You hold the water pipe in the vice, slide the fork onto it locating the bolt head into the damper rod and either use a rattle gun or even a breaker bar with a hex key socket will loosen it for you.

Regards
Viper 79 

[RM Ted]

THANKS,I WILL TAKE ALL THIS ON BOARD AND HAVE A GO ON THE WEEKEND.

[brent j]

A 24mm or 15/16" AF bolt or nut will fit the damper rod.

Weld a bolt to a piece of rod or file a square into a nut and fit it to a 1/2" drive extension bar.

Brent

[crs-and-rms]

how did you go did you get the damping rods out

[RM Ted]

I GOT THEM APART WITH BRENT J'S BROOM STICK IDEA.THEY CAME APART EASY AS.ILL HAVE TO MAKE A TOOL UP AS SUGGESTED TO GET THEM BACK TOGETHER.NOW I CAN SEE WHAT I NEED TO DO.

[crs-and-rms]

tell me what size is the tool 22 or 24 mm