Jump to content


Bolts Loosening on MT-16 Differential

differential loose bolts MT-16

  • Please log in to reply
27 replies to this topic

#1 MTRRAD

MTRRAD

    Newbie Member

  • Members
  • Pip
  • 24 posts
  • Joined:04-August 14
  • Gender:Male
  • Location:Southern Indiana
  • Interests:Old Bikes, farming, Steam engines and the like. It it's old and mechanical, I love it.

Posted 25 January 2015 - 04:11 PM

Does anyone else have the problem of loosening bolts on the MT-16 differential? I've helicoiled the threads, replaced the bolts with high strength ones, and used 3M medium locktight. They still loosen, I have to tighten them every time I go out. I just snapped off one of the original studs, and now will take the whoe thing apart and helicoil and replace those two studs too.
I am about to safety drill and wire them.
Thanks.

#2 dneprlover

dneprlover

    Russian Bike Nut

  • Members
  • PipPipPip
  • 689 posts
  • Joined:16-October 11
  • Gender:Not Telling

Posted 25 January 2015 - 04:26 PM

Helicoiling is quite common as the casting is not usually of the best quality.. I always drill a little deeper and put 1/4" longer than standard screws in with spring washers behind the heads. Personally, I haven't had any problem with the bolts loosening .

Could it be a vibration issue? The sidecar shaft U/J's should always be synchronised on assembly. The one time I forgot to do it ( emergency roadside repair) there was definitely a vibration, rectified when I re assembled it correctly

#3 MTRRAD

MTRRAD

    Newbie Member

  • Members
  • Pip
  • 24 posts
  • Joined:04-August 14
  • Gender:Male
  • Location:Southern Indiana
  • Interests:Old Bikes, farming, Steam engines and the like. It it's old and mechanical, I love it.

Posted 25 January 2015 - 07:11 PM

The bike runs smooth. By synchronized, do you mean the universals have to be 90 degrees out of phase? If so,  I believe they are, but will double check. Since I have to take it apart again, to replace the broken stud, I am thinking of getting that lock up kit from Germany. What is it like? Is it worth it?

#4 yatesfly

yatesfly

    Russian Bike Nut

  • Members
  • PipPipPip
  • 164 posts
  • Joined:15-April 10
  • Gender:Male
  • Location:illinois
  • Interests:motorcycles and airplanes

Posted 25 January 2015 - 08:29 PM

The first summer I had my mt-16 the bolts came loose on my differential I think I noticed leaking oil I tightened them may have used a small,amount of blue locktite don't think I have noticed the problem after that. I don't remember for sure but haven't had a problem since. I don't know about the lock up,kit you might ask bural I think I would fix present problem first. I don't use mine for hard off road so I don't need a lock up kit IMHO. Good luck.  Dennis
dnepr MT16,64 hd xlch,71hd xlh, 82 honda gl500

#5 dneprlover

dneprlover

    Russian Bike Nut

  • Members
  • PipPipPip
  • 689 posts
  • Joined:16-October 11
  • Gender:Not Telling

Posted 26 January 2015 - 04:32 AM

I have a lock up kit on my MB650 and will be replacing it with a standard one soon. Not worth the change in my opinion. It turns the bike into a Ural, but with far worse handling.

#6 Alecu

Alecu

    Russian Bike Nut

  • Members
  • PipPipPip
  • 637 posts
  • Joined:26-April 05
  • Gender:Male
  • Location:Bucharest, Romania

Posted 28 January 2015 - 05:21 PM

@MB650 ith lock up kit...it only turns Uraly it if you select it, otherwise it's the same smooth planetary motion?

@MTRRAD Safety drill and wire them,mine will get loose once in a while, not too frequent though and I have original thread no hellicoil yet.
The single wheel drive is a disaster in terms of the 4 nuts and studs getting loose, I've started putting high quality Zenk bolts from the inside, still will move a little but no place to go, should drill and safety wire the 4.
1963  IMZ M61 rig
1992  KMZ Dnepr MT16
1992  KMZ Dnepr Md 157 Solo
1939 Victoria KR35SN/WH
1941 BMW R12
R1100RS

#7 sallen

sallen

    Russian Bike Nut

  • Members
  • PipPipPip
  • 266 posts
  • Joined:05-March 12
  • Gender:Male
  • Location:Wilmington, NC
  • Interests:My G S Dogs
    Ford T Speedsters
    Dneprs and Urals
    Friends and Food

Posted 28 January 2015 - 10:24 PM

Dneprlover;

Interested in your lockup kit if your selling it.

#8 dneprlover

dneprlover

    Russian Bike Nut

  • Members
  • PipPipPip
  • 689 posts
  • Joined:16-October 11
  • Gender:Not Telling

Posted 29 January 2015 - 04:30 AM

I didn't buy a kit. It is a complete diff assembly that came with the bike. When I do take it off , I an certainly not going to saw off the frame lugs so it would be incomplete anyway. Crownwheels are getting harder to obtain so I will probably hang on to it for spares..( I have 4 x 2wd drive and 4 x 1wd outfits with both l/h and R/h sidecars)
Your best bet would be to buy the conversion kit from motowadim on Ebay. Shipping from the UK would probably be a lot more than he would charge for the kit.

Remember, they were only in production for a very short time by KMZ and there are good reliability reasons why they stopped them. They are certainly not 'soldier proof' and I find the handling very 'twitchy' compared to the other types, especially when pulling a trailer.

#9 Serious Black

Serious Black

    Russian Bike Nut

  • Members
  • PipPipPip
  • 3,636 posts
  • Joined:16-November 04
  • Gender:Male
  • Location:Norway
  • Interests:Bikes
    History
    Engine tuning

Posted 29 January 2015 - 09:58 AM

View Postdneprlover, on 29 January 2015 - 04:30 AM, said:

I didn't buy a kit. It is a complete diff assembly that came with the bike. When I do take it off , I an certainly not going to saw off the frame lugs so it would be incomplete anyway. Crownwheels are getting harder to obtain so I will probably hang on to it for spares..( I have 4 x 2wd drive and 4 x 1wd outfits with both l/h and R/h sidecars)
Your best bet would be to buy the conversion kit from motowadim on Ebay. Shipping from the UK would probably be a lot more than he would charge for the kit.

Remember, they were only in production for a very short time by KMZ and there are good reliability reasons why they stopped them. They are certainly not 'soldier proof' and I find the handling very 'twitchy' compared to the other types, especially when pulling a trailer.

Agree on both count. I managed to explode one - not cheap to fix. Surprisingly enough I found 1WD more effective in snow.
The devil is in the detail.

#10 sallen

sallen

    Russian Bike Nut

  • Members
  • PipPipPip
  • 266 posts
  • Joined:05-March 12
  • Gender:Male
  • Location:Wilmington, NC
  • Interests:My G S Dogs
    Ford T Speedsters
    Dneprs and Urals
    Friends and Food

Posted 29 January 2015 - 09:06 PM

From your post, thought you might be changing out the parts to convert form the MB650 locking to the later MB650/MT16 non locking diff.

The  MB650 locking diff converts the 2WD from a from a standard spider rear axil to a locked axil for off road mud and snow conditions.
It's not for road use.

#11 dneprlover

dneprlover

    Russian Bike Nut

  • Members
  • PipPipPip
  • 689 posts
  • Joined:16-October 11
  • Gender:Not Telling

Posted 30 January 2015 - 01:19 AM

I do know the difference between the Dnepr locking and non locking differentials as I own and ride both types. ( have you even seen a Dnepr with locking diff?) it is simply easier for me to swop complete diffs as I have several spare.

The Dnepr locking diff was only produced by the factory on early MB750 models for a few years in the early 1960's and soon dropped in favour of the full time diff. My MB650 is a genuine one that somebody has fitted one of the original locking diffs to and welded the lever pivot and stop to the original MB650 frame.

The main problem with locking diffs is that when it is locked , the bike does not want to deviate from a straight line and any attempt to steer away from this can result in  either the diff unlocking itself or smashing the units intenals. That is why Dnepr ceased to make ithem.

I know the grass is greener and there are a lot of fables about 2wd as I have learned over the 20years that I have been involved with them. I believe that direct experience beats pure conjecture from sources that have never even seen one apart from photo's on the net

By all means , convert if you wish, I believe you would be making an expensive mistake and it wouldn't perform to your expectations.

The only way to make a 2wd Dnepr out perform a 1wd model in snow or mud, is to put several hundred pounds of ballast in the sidecar

#12 MTRRAD

MTRRAD

    Newbie Member

  • Members
  • Pip
  • 24 posts
  • Joined:04-August 14
  • Gender:Male
  • Location:Southern Indiana
  • Interests:Old Bikes, farming, Steam engines and the like. It it's old and mechanical, I love it.

Posted 31 January 2015 - 07:18 AM

I love this site and all the opinions. If the differential did not have the casting for the locking lever I might not want one, but it does and I do. I really want it for crawling through the mud, but I could see using it to get out of a snow drift. I have about 100K miles in several BMW sidecar rigs. My favorite was my 1953 R51/3 with the Steib S500 sidecar. One wheel drive and not very good in snow or mud. It's not the utility so much, but the neatness of the locking differential. It's just cool. Now I have heard that the Chaingjing has a two speed tranny, four up and four down. Anyone know if that's true, and if they can be adapted to a MT-16. What I really want is a Zundapp K750 that will do 65 mph. I just don't have $35k.

#13 dneprlover

dneprlover

    Russian Bike Nut

  • Members
  • PipPipPip
  • 689 posts
  • Joined:16-October 11
  • Gender:Not Telling

Posted 31 January 2015 - 10:17 AM

They are cool, no doubt about that, but I put reliability first. A cool bike in the garage because spares are unobtainium is not as good as a slightly cooler ( MT16) one on the road. If you do buy a kit, it will come with a machined casing anyway and at least with the MT16's drive shaft, there is less chance of damage than with the heavy shaft of a K750.
The kits are quite easy to install but a little fiddley to get together with the hardest part welding a pivot and a stop to the bikes frame in the correct place. The newer kits have a small handle on the locking plunger for the lever, this can be very stiff and impossible to operate wearing gloves. Make this handle bigger by welding a t bar across it whilst welding the frame.

Re your comment about your BMW outfit in snow and mud. Get any outfit, be it 1wd, 2wd or whatever, and stick the same tyres on it your BMW had on. They will all be crap. Bad conditions need suitabe tyres  and choice of them needs carefull consideration for envisaged conditions.

#14 MTRRAD

MTRRAD

    Newbie Member

  • Members
  • Pip
  • 24 posts
  • Joined:04-August 14
  • Gender:Male
  • Location:Southern Indiana
  • Interests:Old Bikes, farming, Steam engines and the like. It it's old and mechanical, I love it.

Posted 01 February 2015 - 08:43 AM

I've had my MT-16 up to the axels in mud. I was a mile from the barn and did not want to walk back to get the tractor. I left it in gear and climbed off and pushed. It worked. But at the time I really wanted a locking differential. As far as reliability, as long as you treat it right, the locking differential should last as long as any other. I also need to figure out how to get 40 HP out of my motor. I've been wondering if anyone has increased the compression ratio.

#15 Bilge Keel Dave

Bilge Keel Dave

    Russian Bike Nut

  • Members
  • PipPipPip
  • 1,282 posts
  • Joined:28-January 04
  • Gender:Male
  • Location:Olympia, WA
  • Interests:Beautiful Wife, Beer, Bikes, Boats, Books, British Cars.

Posted 01 February 2015 - 10:38 AM

I ported the heads and matched the intake ports to the carburettors and I opened up the exhaust ports by about a third. I also put some free flowing Harley mufflers on it. I haven't dyno'd it, though my butt dyno noticed a difference.

Dave
RAMCO Dnepr MT-16





Also tagged with one or more of these keywords: differential, loose bolts, MT-16

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users