Gearbox & Overdrive Rebuild. Rebuilding the Overdrive. Part Five

[@getover60]

Well took a while but I found a Sunbeam 4speed and laycock, these videos are invaluable. The job is to remove my input shaft from a doner Jensen Healey Roots 4 speed and put in the Sunbeam, as bell housing and clutch spline are different for the Lotus Engine. Also to inspect for damage, and clean up anything.

[@TheSunbeamAlpineChannel]

Dale, I am pleased that the videos are of use to you. We have published over 100 videos on The Sunbeam Alpine Channel on KZbin, we hope that you make use of all of them (and like and subscribe!)

[@guitarmor5292]

Hi, What oil would you recommend to fill the gear box with and when the OD unit has been drained does re filling the gear box with oil re fill the OD unit as well?

[@TheSunbeamAlpineChannel]

We use 20/50 Millers classic oil, the same as in the engine but some people prefer straight 30. When you fill the gearbox to the level of the filler plug you have also filled the overdrive.

[@guitarmor5292]

@@TheSunbeamAlpineChannel thank you. 🙏

[@stevenarcadia2036]

Hi, I just found your channel and a credit to you for all of the great info. When inspecting the clutch material what would be the minimum thickness before replacement? Is there anything to look for when deciding to replace?

[@TheSunbeamAlpineChannel]

Hi Steven, I hope you will subscribe to our channel and enjoy our videos. We usually take the view that unless we know the history of the clutch and it is a recent one, we replace all three parts when we have the engine and transmission split. When you consider the relatively low cost against the effort of splitting the engine and gearbox it seems worthwhile. We make no claims to be mechanics or experts, just Alpine enthusiasts. I can't see a minimum thickness recommendation anywhere in the workshop manual, it just refers to 'replacing if it is worn down to the rivets' (which is a bit too late really!)

[@hubertyvon7970]

Hi , i have my overdrive off. After cleaning ( no dismentle ) , i can't line the splines . With a long screwdriver no splines can move ( up or rear ). Thank you for your help. Well done channel.

[@TheSunbeamAlpineChannel]

Hubert, have you managed to line this up yet? If not I will contact John and see if he can advise you.

[@engtech10]

You mention the individual planet gears have a punch mark and an etch mark. I see the timing is NOT on the punch mark but instead on the hard to see Etch mark which could be either the high or the low. This seams to be different from other info.

[@TheSunbeamAlpineChannel]

I have discussed your question with John Roseby, this is his answer. Ok so you find the punch marks, sometimes not easy. Then 1 of the etch marks will be to the right of the punch, 1 will be to the left and the other on the same tooth as punch mark. Markings are max and min runout, if 1 tooth out it can be diff to assemble.

[@TheSunbeamAlpineChannel]

For clarity John contacted me again and asked me to make clear that there are 3 etch marks. One is on the 4th tooth to the left of the punch mark, one is on the 4th tooth to the right of the punch mark and one is on the punch mark. He puts an extra visible mark on each one once he has located them to ensure that everything is lined up correctly. I hope that this helps.

[@engtech10]

Hold the planet gear like a clock face with the overlapped etched&punched gear @ 12 o'clock and the scribe "S" at the bottom. The 2 lower gears are now Left 8 O'clock & Right 4 O'clock the etch location will also reference this left & right from punch marks. @@TheSunbeamAlpineChannel

[@getover60]

how do I get to part 1 ?

[@TheSunbeamAlpineChannel]

Hi Dale, just search The Sunbeam Alpine Channel on KZbin and on the homepage click the “videos” bar. There are 80+ videos there, the gearbox ones are towards the bottom of the list. Best Wishes, Tim

[@engtech10]

I just completely disassembled my planet gear down to the housing and found oil passages inside each of the 3 gears shafts. The only way to clean those passage is with a jewelers screw drive. Not even hours in a Simple-Green and then mineral spirit sonic bath could reach that stuff. Word of caution to you re builders don't just inspect the planet gear!

[@TheSunbeamAlpineChannel]

Obviously you want any oil ways to be clear of any debris, just be aware that some of the oil holes do not go all the way through the shafts, they are blind holes. The shafts are not normally removed when reconditioning.

[@engtech10]

I mention the oil passages inside each planet gear shaft because each of the 3) has 2) B-78 needle bearings inside them. The oil to the gears passes through one end of the shaft to a center outlet hole that feeds both B-78 bearings. Over looking the planet gear assembly could easily result in 6) bearing failures due to blocked oil passages. @@TheSunbeamAlpineChannel

[@TheSunbeamAlpineChannel]

Good luck with your restoration.