Bolt too short for my MR 4800

Model A

New member

Equipment
B 6100 hst
Aug 24, 2016
2
0
0
Monterey,Tn.
I had the center of my mr 4800 box rebuilt when I got it the center blade had fell off after the center rebuilt the center bolt that holds the center blade on is to short and the mower last about 30 mins. before the blade sails off.
my local dealer rebuilt the box and I bought all washers and blade connections didn't seem to help , neither could my dealer, I need a bolt to hold the blade on to be 1/2'' longer, anyone else have this problem? I am using a B6100 HST tractor.
 

CountryBumkin

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Lifetime Member

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BX2370 w/LA243, Bucket, Grapple, QA Pallet Forks, 60" MMM, rear blade & rake
Sep 27, 2015
568
2
0
Central FL
Could the first 1/2" of threads be stripped?
Without the blade, does the bolt thread in to the center shaft and catch threads immediately (or does bolt go into the shaft a 1/2" first before it hits threads?

Did you compare the length of the "too short" center bolt to one of the other bolts used to retain one of the other blades (maybe rebuilder provided/used the wrong length bolt in there)?
 

D2Cat

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L305DT, B7100HST, TG1860, TG1860D, L4240
Mar 27, 2014
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40 miles south of Kansas City
Model A, good to have you here. Hope we can come up with a solution to your problem.

Your sentence, "I had the center of my mr 4800 box rebuilt when I got it the center blade had fell off after the center rebuilt the center bolt that holds the center blade on is to short and the mower last about 30 mins. before the blade sails off" has me a little confused.

Take one of the outside blades off and see if the bolt you remove fits into the shaft on the center. Is it the same diameter and length as the center bolt? Does it thread in as it should? Don't force anything with a wrench. It should thread in by using your fingers.

My guess is your bolt for the center blade is too short. Or the rebuilder installed a different shaft then original in the gear box.

Let us know what you discover.
 

Model A

New member

Equipment
B 6100 hst
Aug 24, 2016
2
0
0
Monterey,Tn.
Thanks I will try other bolt from 1 of the other blades, my bolt that comes loose does only catch about !/4 of threads,
 

North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
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113
Sandpoint, ID
The bolt on that center spindle / blade is in fact supposed to be longer than the 2 side spindles / blades.
If you take off a side blade and the center and side bolts are the same length, they installed the wrong bolt. :(

Side spindle bolts P/N 01173-51628
Center spindle bolt P/N 70720-34370
 

Hosanders

New member

Equipment
B6100
Jul 12, 2020
8
0
1
Southlake TX
I had the center of my mr 4800 box rebuilt when I got it the center blade had fell off after the center rebuilt the center bolt that holds the center blade on is to short and the mower last about 30 mins. before the blade sails off.
my local dealer rebuilt the box and I bought all washers and blade connections didn't seem to help , neither could my dealer, I need a bolt to hold the blade on to be 1/2'' longer, anyone else have this problem? I am using a B6100 HST tractor.
I need my gear box rebuilt. My life cal Kubota dealer won't do it. Can you share your dealer information please?
 

Jim L.

Active member
Jun 18, 2014
811
86
28
Texas
I need my gear box rebuilt. My life cal Kubota dealer won't do it. Can you share your dealer information please?

You might look at Sixth and Mango in Frisco; Zimmerer Kubota in Denton; Dentex Tractor Service in Denton. Maybe ask at Cabela's who does their tractor work.
 

Hosanders

New member

Equipment
B6100
Jul 12, 2020
8
0
1
Southlake TX
I need my gear box rebuilt. My life cal Kubota dealer won't do it. Can you share your dealer information please?

You might look at Sixth and Mango in Frisco; Zimmerer Kubota in Denton; Dentex Tractor Service in Denton. Maybe ask at Cabela's who does their tractor work.
Thanks for the lead on Dentex and Sixth and Mango. I called Zimmerer in Denton - no help.