Need 312-8 trans info - bolts into top of Transmission?

[Brockport Bill 1,368]

I am newbie to site past couple of months but seems to be abundance of people and info to help those of us that need WH wisdom? I own 1989 WH, original owner, 312-8 --  always did basic care and maintenance -- tractor in pretty good condition after 31 yrs -- now being brave and starting more complex maintenance efforts and some modest  restoration and painting some parts -- disassembling is risky adventure although i have ok brain for this stuff -- so i took off seat and seat pan and gas tank, and footrests, side panels - however, there is a large support bracket hardware on the back of tractor that holds gas tank - it has a base that sits on top of transmission with two bolts that go down into the top of the transmission housing -- i unscrewed the two bolts and took off the bracket to discover the two bolts do in fact go into the top of the transmission -- with a flash lite it appears bolts actually go into the transmission and looks like i can see the gears -- Yes/no? 

 

what concerned me is the two bolts i removed had "gunk" not appearing to be clean tranny fluid on the ends of both bolts - its been a few years since transmission fluid was changed -- and likely few hundred hours - - I assume overdue for tranny fluid to be drained and replaced ???  Questions: #1: - should i be concerned of the material i found on end of the two bolts - "gritty gunk" ?-----  # 2: any tips or hints to drain and replace the transmission fluid? Lastly #3: -- any reason to spend the $ to have the transmission pulled apart and needing attention other than fluid change? Tractor runs fine and tranny seems  generally ok  Many thanks for insights anyone may offer. Bill

[Maxwell-8 4,270]

on , The bolts tread indeed into the tranny, I have one open for the moment, and i do have a different type of gunk up then under in the tranny.

I am pulling it apart, and cleaning. I think its good to do, on these older trannys, that way you can check for worn bearings. Just a new gasket, but apart from that it's free. It gets you  a good peace of mind.

 

If you are just changing oil, drive a bit with the tranny, lift the front up high, remove the allen head bolt underneath the trans: best way to drain all the oil. Look for water/metal flacks in the oil.

 

I had clean oil coming out: but the inside looked a bit different:

Edited January 28, 2021 by Maxwell-8

[Ed Kennell 35,626]

1 hour ago, Brockport Bill said:

Questions: #1: - should i be concerned of the material i found on end of the two bolts - "gritty gunk" ?-----

                                      I would just do a flush cleaning.

  # 2: any tips or hints to drain and replace the transmission fluid? Lastly

                                      Find the drain plug on the bottom right of the tranny.  Clean out the 1/4" socket head  pipe plug.    Raise the front of the tractor as high as you safely can to permit the oil to drain over the hump that is across the bottom of the tranny.    If the oil looks really bad, I would fill the tranny with kerosene or diesel and run it thru all the gears for a few minutes to flush out all the old oil.

   Refill with 90W gear oil.

#3: -- any reason to spend the $ to have the transmission pulled apart and needing attention other than fluid change? Tractor runs fine and tranny seems  generally ok  Many thanks for insights anyone may offer. Bill

    If it is working fine with no excess or changing noise, I would not open it.   It can be a real challenge to remove the hubs.

 

 

                                                

[953 nut 51,541]

1 hour ago, Brockport Bill said:

Questions: #1: - should i be concerned of the material i found on end of the two bolts - "gritty gunk" ?-----  Since you have been servicing the tractor from day one the only thing you probably need to do is replace the old fluid with some fresh  gear oil.

# 2: any tips or hints to drain and replace the transmission fluid? There is a bit of a hump in the middle of the transmission, to drain it you should jack up the front of the tractor so oil won't be trapped in the front half.

#3: -- any reason to spend the $ to have the transmission pulled apart and needing attention other than fluid change? Tractor runs fine and tranny seems  generally ok  Many thanks for insights anyone may offer.If the transmission has been providing good operation I would leave it alone.

@Ed Kennell types faster than I do.

[WHX?? 46,704]

Real good advice from Ed and Richard. Yes if it ain't broke dont fix it but i would do a flush just for drill.  Thread the bolts back in and clean around them to keep dirt from falling in. I like to fill through those holes too. I also like to use a magnetic drain plug. If you want one I can send you one, I make them. 

[BeninCT 451]

I have an 88 310-8 and it had a gear whine from the rear that I think has gone away with a fluid change.  I used my oil sucker device thing to suck it out from the dipstick hole first then the fill plug with tractor jacked up on R side.  Then put plug back in and filled it.  

 

Fluid was a red muddy looking mess and will do oil change a couple more times this year depending on use.  I would start with a fluid change b/c its quick and see how it goes.  You can monitor the oil appearance on the dip stick.

[Brockport Bill 1,368]

i checked the fluid via dip stick and its a mostly medium to slightly dark brown --- typical consistency ---  i am not familiar with what it should look like - curiously, the operators manual does not list a transmission fluid replacement schedule??  it states " changing lubricant is NOT required except for major service "............ What the heck does that mean - what's an interval for " major service"???????????

 

thanks for all the guidance - I did navigate the other past topics and responses on the site since i wrote this and there is really helpful info about the flushing and replacement fluid . many thanks -- i welcome all added advice - 

[Maxwell-8 4,270]

7 hours ago, 953 nut said:

If the transmission has been providing good operation I would leave it alone.

 

7 hours ago, Ed Kennell said:

If it is working fine with no excess or changing noise, I would not open it.   It can be a real challenge to remove the hubs.

Understandable, for sure, if someone ain't that experienced, but for me, i open them up: 1) i have to remove the hubs, cause my seals are all leaking. And 2/3 of my trannys had moved outer bearings. I prefer to open it, fix it and clean the gunk you always have out.

 

I hope you guys have more tranny luck!

[stevasaurus 22,229]

Bill, you have discovered the best way to look into your transmission.  You can see the differential and maybe the mushroom gear through those holes.  If those gears look clean, take a long screw driver and see if you can insert it and reach the bottom of the casting.  Try to scrape a little and see if you bring up any sludge.  If so, flushing may not clean that out.  It is probably safe to say, your 1989 horse has never had the transmission fluid changed.  It all depends on what you can see in there.  If you think you should open it up to really clean, I would still do a good flush, but for longer then a few minutes...20 to 30 minutes is better.  Do not drive it around on your lawn...if the seals start leaking during the flush, you lawn may show where you drove it.  Street, sidewalk, neighbors lawn you don't like...or put rear end on blocks would be best.  

   To answer your question about complex maintenance...depends on amount of use and what type.  I think 1 to 5 years and check it periodically would be safe.

[Brockport Bill 1,368]

thanks for great insights -- before i respond i see your Navy reference -- thanks for your service to our nation, I have Navy fondness -  my Dad was navy aviator WW 2 flying various sea plane patrol bombers over the pacific -- including PBY's and BIG Marlin Mariners - ----- then 25 years in the reserves -- flying P2V Neptune up and down the Atlantic coast one weekend a month looking for Russian subs - my sisters and I loved his Navy experience -- BACK to tractor talk - again thanks for info - i did find some other  helpful posts on the forum -- echoing your suggestions -- I think i might do the flush as suggested -- diesel or kerosene - couple times, and drive the neighborhood , changing gears etc  - then replace with new fluid -- Actually, my tranny did have new fluid about 4 yrs ago from local WH shop - maybe about 500-600 hrs since change - - curiously the manual does not recommend trans change except for major service but does not specify the duration -- weird!!! I don't want to venture disassemble myself -- and if possible avoid the cost to take to a shop so i'll try simple flush and change solutions first - - plus your screw driver test -- STAY WELL

[953 nut 51,541]

5 hours ago, stevasaurus said:

neighbors lawn you don't like.

So glad I'm not in your neighborhood!             

[WHX?? 46,704]

Everone here thanks your dad for his service. 

1 hour ago, Brockport Bill said:

drive the neighborhood

[jhn9840 35]

Does anyone know if there is a service manual for this particular transmission?

 

jhn9840

John

[Brockport Bill 1,368]

i found these numbers on my transmission  - on the rear label of Uni Drive - #2988185 -- then on the brake side in raised numbers - I cleaned them but still hard to read for certain --- #111198 - then a second # 111203 - then nearby in small raised numbers the number 55 then also the number 9 -- 

i have no idea what all these numbers indicate? if that means something to the wise brains on the forum I'd be interested to know - thanks Bill

[gwest_ca-(File Mod) 10,488]

This should be the transmission you have

Section V for the 8-speeds

 

[Brockport Bill 1,368]

terrific -- thank you