Over the winter iam planning on some gearbox work I currently have a series 2 with a 1098 engine on a 948 box with retaining the wand stick,recently came into 2 1098 boxes and another 948 so I've decided to chop the 948 for a spacer plate to convert my 1098s to retain the wand stick. I have some questions about this
Is there anyone close as possible to bridgend South Wales who can take alook at the boxes(1098) and identify what parts would need to be renewed for starters
Secondly does anyone have any info about how to go about converting the above have seen a post on here in which other members have been mentioned in the post but the search I do only brings up this one guide if you are the persons who have done or anyone else who knows how to undertake such tasks possibly contact me many thanks all!
Over the winter gearbox
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myoldjalopy
- Minor Legend
- Posts: 2533
- Joined: Tue Jan 29, 2013 10:32 pm
- Location: Kernow
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Re: Over the winter gearbox
Its a bit complicated and I have never done it, but I found these instructions in an old 1989 copy of Minor Matters Tech Tips:
The components are not immediately compatable because the rear ball race of the 1098 gearbox is of a larger outside diameter and positioned about 3/16" further back than on a SII box. Therefore, a spacer plate made from 3/16" aluminium must be fitted between the 1098 casing and the 803 rear extension (seems a shame to chop your 948 box), a gasket can be used to make a pattern for the plate, remembering to put all the oil holes and a hole for the locating peg on the steel bearing housing. A blind clearance hole needs to be drilled into the face of the 803 rear extension to take the end of the locating plate.
Unfortunately, the speedo drive pinion is now about 3/16" too far back and will mesh with the nut and washers on the main shaft instead of the speedo gear. This is overcome by by putting a 0.1" thick spacer between the speedo drive gear and the distance piece on the main shaft, the diameter of the spacer being identicle to the distance piece, and by chamfering the far end of the teeth of the speedo drive pinion.
With the whole thing together with a gasket either side of the spacer plate and 3/16" longer screws there then needs to be a small slug of steel welded into the bottom of the slot in the reverse selector rod to prevent accidental selection of reverse when selecting fourth. (This then retains the 'up and over' 803 reverse gear select mechanism).
Before assembly, a new combination of bearing packing washers for the rear cover will have to be selected, as detailed in section FF8 of the Workshop Manual.
To fit to the car, because of the additional 3/16" now added, the two slotted holes in the gearbox mounting cross member must be widened. Also, with a 1098 engine,bgearbox and 4.22 diff in a SII, the correct speedo head must be fitted to match the axle ratio. The 'works' from the large diameter later type speedo will fit into the casing of the small diameter head fitted to SII cars but the dials have to be interchnged and rescaled.
I hope this all makes sense to you, but I stress I have never attempted this and make no claims for its accuracy. Nevertheless, I hope this helps. I also wonder if an 803 reverse selector rod - if you had one to hand - could be used instead of welding the slug of steel as described.
Cheers,
Pete
The components are not immediately compatable because the rear ball race of the 1098 gearbox is of a larger outside diameter and positioned about 3/16" further back than on a SII box. Therefore, a spacer plate made from 3/16" aluminium must be fitted between the 1098 casing and the 803 rear extension (seems a shame to chop your 948 box), a gasket can be used to make a pattern for the plate, remembering to put all the oil holes and a hole for the locating peg on the steel bearing housing. A blind clearance hole needs to be drilled into the face of the 803 rear extension to take the end of the locating plate.
Unfortunately, the speedo drive pinion is now about 3/16" too far back and will mesh with the nut and washers on the main shaft instead of the speedo gear. This is overcome by by putting a 0.1" thick spacer between the speedo drive gear and the distance piece on the main shaft, the diameter of the spacer being identicle to the distance piece, and by chamfering the far end of the teeth of the speedo drive pinion.
With the whole thing together with a gasket either side of the spacer plate and 3/16" longer screws there then needs to be a small slug of steel welded into the bottom of the slot in the reverse selector rod to prevent accidental selection of reverse when selecting fourth. (This then retains the 'up and over' 803 reverse gear select mechanism).
Before assembly, a new combination of bearing packing washers for the rear cover will have to be selected, as detailed in section FF8 of the Workshop Manual.
To fit to the car, because of the additional 3/16" now added, the two slotted holes in the gearbox mounting cross member must be widened. Also, with a 1098 engine,bgearbox and 4.22 diff in a SII, the correct speedo head must be fitted to match the axle ratio. The 'works' from the large diameter later type speedo will fit into the casing of the small diameter head fitted to SII cars but the dials have to be interchnged and rescaled.
I hope this all makes sense to you, but I stress I have never attempted this and make no claims for its accuracy. Nevertheless, I hope this helps. I also wonder if an 803 reverse selector rod - if you had one to hand - could be used instead of welding the slug of steel as described.
Cheers,
Pete