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General Category => General Discussion => Topic started by: arveno on March 30, 2015, 09:58:37 PM

Title: Ambo front wheel play
Post by: arveno on March 30, 2015, 09:58:37 PM
Hi All
front wheel of my ambo has a little bit of play
I read this instruction on G.Bender website but i do not get it  ??? can someone share pics and how to shim front wheel bearing ?

http://www.thisoldtractor.com/moto_guzzi_loopframe_wheel_bearing_adjustment_shimming_set_up.html

Thanks
Marco
Title: Re: Ambo front wheel play
Post by: canuck750 on March 30, 2015, 10:31:46 PM
Wish I had more pictures of this, but this photo shows what happens when the shimming is not correct!

(http://i249.photobucket.com/albums/gg217/canuck750/1972%20Moto%20Guzzi%20850%20Eldorado/August102012004.jpg) (http://s249.photobucket.com/user/canuck750/media/1972%20Moto%20Guzzi%20850%20Eldorado/August102012004.jpg.html)

So like Greg explains first remove the bearings and the bearing spacer and wash everything as clean as you can and dry the parts.

Then lightly oil the bearings, no grease yet.

Reassemble the tapered roller bearings onto the bearing holders, (the little metal pieces that slide into the bearing), the races are in the wheel hub at this point, fit the bearing spacer (the long steel section of steel tube) that sits inside the wheel bub and into which a bearing carrier fits onto each end of the tube. At this point you are balancing the wheel vertical on a bench, one hand on each side of the bub and you are pressing the bearings tightly together into the hub.

Now apply pressure with each hand pressing the bearings together, there should be very, very little side to side play  - too little and bearing will collapse - too much and the bearing will wobble itself to pieces.

The shims fit between the 'tube' spacer and one of the bearing holders.

You want just a few thou clearance, I sometimes turn the spacer down a few thou in my lathe if the shims I have are too thick.

When you got it right pull the bearing s out and grease them up, refit and install the grease seals.

Title: Re: Ambo front wheel play
Post by: rodekyll on March 31, 2015, 12:33:58 AM
0.004 - 0.008" freeplay accoding to my old notes.

I also have a note about converting to ball bearings.  I don't remember if I did or not.  Wouldn't they be easier to set up?
Title: Re: Ambo front wheel play
Post by: Kiwi_Roy on March 31, 2015, 04:40:13 AM
Ball bearings may be easier to setup but they won't last like a tapered roller IMHO.
I'm pretty sure the rollers in my Eldorado are the originals put in 140,000 miles ago but
my California II when I pulled it apart had 4 different makes of bearings, My EV just
had a front collapse and the V11 Sport have all been replaced.
Title: Re: Ambo front wheel play
Post by: rodekyll on March 31, 2015, 04:53:46 AM
Ball bearing = $8.

Taper roller = $140

Besides easier setup and maintenance and available at the slurpee counter, that's all I've got.
Title: Re: Ambo front wheel play
Post by: arveno on March 31, 2015, 09:35:18 AM
Thank you all for the helps , I finally found a pic in a moto guzzi manual and now is clear to me where the shims have to go .

Question : the manual says that if the wheel does not spin freely it will need to add shims , if the wheel has too much free play , shims needs to be taken out .

Did I get it right ?

Thank you again ,
Marco

http://www.thisoldtractor.com/mg_manuals/workshop_manual_chilton.pdf

Page 133 :

Front Wheel
1. Assemble the taper roller bearing,
bearing housing, and seal ring to the right
side backing plate.
2. Assemble the bearing distance collar,
adjusting washers, taper roller bearing,
bearing housing, and seal ring to the lefthand
backing plate.
3. Check for excessive end play and alleviate
it if necessary by removing one adjusting
washer. If the wheel does not
rotate freely, it will be necessary to add
washers until the desired results are ob- '
tained.

Title: Re: Ambo front wheel play
Post by: Chuck in Indiana on March 31, 2015, 10:11:47 AM
Aaah, Guzzi manuals...
Title: Re: Ambo front wheel play
Post by: jrt on March 31, 2015, 07:41:59 PM

Question : the manual says that if the wheel does not spin freely it will need to add shims , if the wheel has too much free play , shims needs to be taken out .


Rather the opposite.  If there is too much free play, then it needs a shim.
Add one shim at a time, checking for free play between each addition.  At some point, you will add one shim too many and the bearings will start to bind up.  Remove that one shim and it should be about right. 
Title: Re: Ambo front wheel play
Post by: rodekyll on March 31, 2015, 07:52:49 PM
I posted the freeplay range.  You need shims adjusted/added/subtracted/replaced with another size if the play is either looser (add thickness) or tighter (remove thickness) than specs.

Trivia point -- when setting up front wheel tapered roller bearings on most cars, the freepllay is considered in range when you come off of bind and can just freely slip the spacer between the nut and the bearing  -- sort of how a loose feeler gauge feels at the correct gap.  I've used that principle for ambo bearings (and steering head bearings) for years with success.

Another trivia point (not directly applicable to the OP) -- threads are pitched predictably. 1.0mm/turn is pretty common for valve adjusters and steering head posts.  That means for every 1/4 turn of the 1.0mm-pitch nut you move ~0.010".  Handy if you need to ballpark valve lash or figure the taper roller bearing gap without feeler gauges.
Title: Re: Ambo front wheel play
Post by: Dick on April 01, 2015, 07:16:33 AM

Question : the manual says that if the wheel does not spin freely it will need to add shims , if the wheel has too much free play , shims needs to be taken out .

Correct.
Title: Re: Ambo front wheel play
Post by: Chuck in Indiana on April 01, 2015, 10:23:32 AM
Correct.

Ok, I'm confused, my normal state.  ;D What am I not understanding?
Title: Re: Ambo front wheel play
Post by: Antietam Classic Cycle on April 01, 2015, 10:33:56 AM
Ok, I'm confused, my normal state.  ;D What am I not understanding?

Dick and Marco are correct. If the bearing play is too loose, you remove a shim. If it's too tight, you add a shim.
Title: Re: Ambo front wheel play
Post by: arveno on April 01, 2015, 12:38:10 PM
Dick and Marco are correct. If the bearing play is too loose, you remove a shim. If it's too tight, you add a shim.

ok , got it , thanks  :)

btw Charlie , i installed the carbs last sunday , and fired her up ... she purrrrrrr like a kitten  ;-T