seeking advice for lla transmission rebuid

[mcb]

The transmission in my 11a has developed lots of slack and some occasional grinding noises (the broken lay shaft was replaced by a proffesional mechanic 3 yrs ago). I'm gonna take it apart this week and plan to replace any broken parts, check for proper sized thrust washers and replace all bearings. I would appreciate any advice- do's/don'ts, etc. from those who have done this!

Thanks - C. Brown

[greenmeanie]

It probably sounds condescending but get the green bible read it, read it again and then take it out to the garage with you. Everything you need to know is in there if you are a compitent mechanic. As you are about to rebuild a gearbox I'll assume this is the case.

You'll need a conical tool to get the split ring on over the shoulder on the mainshaft.
Heat your bearings in the oven for about 1/2 hour at 250°F. They'll just drop onto the shaft if you get them there quickly. Wait until you wife is out before using the oven. Any bearing you hammer on needs replaced. If you apply force across the races (I.e. pulling on the oute rrace to remove a shaft from the inner race.) a bearing needs replaced.
It also helps to have three hands when putting the gears together when installing the bellhousing at the end.

[StX_Rovers]

Look into getting a good quality set of split ring pliers, the kind that work on split rings that do not have the holes. This will simplify dis-assembling and reassembling the gears on the main shafts. S-K makes a good one.

I second the suggestion of reading the entire transmission section of the green bible. Also, if you want to help preserve your copy, xerox the sections you need and take THOSE out to the workshop which minimizes the grease smears etc. on the $120.00 manual.

If you know that you will be doing the rebuild within the time period that you do not have to pay a restocking fee, think about getting one of each size of thrust washer and similar parts. Then return the sizes you do not need. That speeds the reassembly process.

If the oven trick does not work for pressing the bearings onto the shafts, use a piece of aluminum pipe and press or tap on the bearing making sure you are pressing on the INNER race. As mentioned, using the outer race to hammer on a bearing that goes onto a shaft. Make sure the inside of the pipe is clean. I must be fortunate, my wife would be helping me with the bearings in the oven. OF course, her daily driver is a 67 2A 88 RHD hardtop.

All the fasteners are BSF, make sure you have a set of proper wrenches. 5/16 and 3/8 BSF will do most of the transmission.

You will need the cute little tool to remove the nut on the end of the mainshaft gear that is in the transfer case. I think RN sells a version of this tool for not much money. I made my own using a waterjet machine but at the time the tool was not available.

Get 4 new locknuts for the big bolts and studs that attach teh main case to the bellhousing. Also use red loctite. If they loosen up you will have to at least partially pull the transmission to tighten them. There is a reason I am making this suggestion........ You will have to use heat to remove them the next time you overhaul the transmission but hopefully this is not a regular occurrence.

Remember, these things are designed to be maintained by drunk missionaries in the middle of the Kalahari. Just go step by step.

[Jeff Aronson]

If you find pitting on the teeth of any of the gears, or on shafts themselves, consider replacing them at the same time. It's a lot of labor for just washers and bearings.

Keep everything really clean when you work on it. You don't need to insert grit and metal shavings into your transmission.

Jeff

[Les Parker]

All good info.
Yes, RN sells the mainshaft tool:-

http://www.roversnorth.com/store/searchadv.aspx?SearchTerm=rnt0002

Also, when assembling the trans. , you'll find that completing the bell-housing fitment is easier with the trans. stood on its end, i.e. with the weight on the handbrake drum (vertical)

[gudjeon]

When it comes to replacing the small rear pocket bearing race, Use the principle of hydraulics to with draw the race. This little thing is pressed in a dead end recess in the rear of the housing. I do want to see any more holes drilled so a punch can be used. :nono:

To with draw this thing is pretty straight forward and it has never failed me:

-Strip the trans housing
-Turn a large wooden dowel to just fit the pocket bearing race's diameter
-Heat the rear portion of the housing (I did this over my shop's woodstove)
-Place rear housing facing up on a flat block of wood on the floor
-Place some gear oil in the bearing recess
-Inset dowel and smack sharply with hammer
-If stubborn, re-apply oil and hit harder.

Out she comes and no hole drilled. Tolerances are pretty forgiving so don't be too concerned if you are at the max or min of a clearance spec. Read the manual word for word and understand each step before you proceed.

:thumb-up: