Technical Archives
Technical Archives
This page was last updated on $Date: 1999/01/07 01:58:21 $.
Well, the clutch thing is gonna force me to take the gearbox out. Anyone have any hints, aside from what the manuals say? The gearbox itself looks refreshingly unmolested, down to its proper green paint. The mounts, surprisingly, look pretty good, though I'll probably change them since this is a good opportunity to do so. I'll also be able to fix the O/D cutout switch (I get O/D on every gear, which would disasterously include reverse).
The manual sez put the rear of car on axle stands, undo everything, supporting the engine, of course, and then use a trolley jack to slide the 'box away from the engine. This assumes that you'll be removing the box via the underside of the car.
I've heard it said that pulling it out through the inside is better. In this case, do you jack up the front of the car instead? Hints welcome!
Also, I noticed that there's a lever on the right side of the O/D, which has a hole in the small end. It's number 13 in the Bentley manual, P. 196. There seems to be a matching hole on the casing, but on mine there's nothing connecting them, and I don't see any such part in the diagram. I'm gonna assume it's pure coincidence, since the O/D works fine. Let me know whether I should be worried.
--Roger, thinking "135 lbs...my back!"
Peter and Roger each wrote a comprehensive response to Roger's question. Both outlined the same process while emphasising different details. I've taken the liberty to combined both in to a single procedure. Also check out Olin Kane's article, he used a different technique - ed.
First of all, take the gearbox out through the cockpit. If you look around carefully underneath the car you will see that there is way too much superstructure below the gearbox to drop it down.
Remove both seats, gearbox tunnel, gear lever (watch for not only the three nuts and lock washers but three spacer washers nested in the thick rubber pad under the cup). Consider removing (or covering) the carpet if the gearbox is greasy, oily, dirty, etc.
Lay a piece of 3/4" board that can span from the edge of the frame by the gearbox across the passenger side outer sill (side rail). This is to give you something to rest the gearbox on and protect the aluminium door facing on the threshhold.
Remove the rectangular fire wall panel that the gearbox cover butts against. If you have a overdrive, unplug wiring harness from the overdrive solenoid and free it from clip on the overdrive.
Remove all the engine/gearbox bolts that you can reach through the cockpit. This should include the top bolt for the starter. Pay attention to which bolt comes out of which hole. Two of them are special "dowel bolts" which are crucial to keep the gearbox in proper alignment.
Remove the clutch slave cylinder.
Mark the gearbox output flange and the drive shaft so that you can get the alignment right when you put the car back together. Disconnect the drive shaft and push back towards the differential.
NOW jack up the car and set on 4 stands (need to keep the car level). The engine is being held to the gearbox by the bottom two bolts (or three or so) and there is no risk of it coming apart.
Undo the rear gearbox mounts from the frame and the engine/gearbox tie rod from the frame cross member. Leave the mounts attached to the gearbox.
Place a hydraulic piston (bottle) jack under the engine pan. Use a 3/4" board against the pan (with carpet or towel pad if it is in "show" painted condition) and a steel plate 1/4" thick and 3-4" square to spread the load from the jack punch point. Pump the jack until the boards just rest against the pan bottom and supports the engine slightly.
Remove the starter. Take out the bottom bolt and pass the starter forward into the cavity below the heater blower and feed down by the frame. Use towels to protect against scratching the starter, engine or frame if this is of concern. Remove the remaining (should be about three) bolts across the bottom of bell housing.
Place a floor jack with the pad built up about 3-4" using wood blocks under the cast iron gearbox housing. The blocks will fit up between the main frame rails when the jack is raised and prevent interferrence from the jack arm hitting the frame. Jack up until contact is made. Then jack up the gearbox a bit and raise the jack under the engine so that it "keeps up" with the raising of the gearbox. Repeat the raising of both jacks, a little of each at a time. Check from the cockpit to see that you don't go too far. The top flange of the bell housing must clear the fire wall/scuttle when the gearbox is drawn back into the passenger compartment. Also, pay attention to how much room you have between the fan and the radiator when you do this.
When you've raised engine and gearbox as far as you think you can, stand in the passenger compartment with one foot on either side of the drive shaft tunnel. Grab the gearbox and it slide back, using the wood on the floor jack under the housing as a resting surface. You will need to keep it from rolling left or right, but should not have to support much weight on your own, yet.
You may have to play around with the jacks a bit at this point to get the weight of the gearbox off of the input shaft. Patience!! Also, you may have to rotate the gearbox a bit to get it clear of the fire wall. It _will_ come out eventually.
Slide the tail of the gearbox into the drive shaft tunnel (that's why you got the drive shaft out of the way.) Once the input shaft is clear of the clutch release bearing, grab the top front of the bell housing and the rear drive flange, lift and slide gearbox to passenger side and rest it on the board I mentioned at the top. Slide towards passenger door, and reposition yourself to lift it out of car (a strong son helps at this point - as Peter's strong son, Matt, pointed out).
Watch out for hand brake handle -- you may need to LOWER in order to pass gearbox over it.
This is a good time to check the clutch, the ring gear, the ground strap, and the pilot bushing(ed.).
A note during reassembly of the gearbox: When reassembling the gearbox, don't put the side cover on until after you have mated the gearbox with the overdrive and the bell housing. That way you can run it through the gears to make certain it all works correctly.
Installation is the reverse, except use the floor jack to control its height until you think it is a good match to the engine. The gap between bell housing and rear engine plate must be close to perfectly uniform left to right and top to bottom in order for the spline and pilot to line up. Use the jacks and pivoting motion on the wood jack block to make fine adjustments. When you think things are right, push it home. It is a good idea to have the gearbox in gear so that you can rotate the input splines by turning the output shaft. 4th gear is the best choice for this. Insert the bottom two bolts first and then lower the gearbox and engine keeping the two jacks fairly even with each other. Insert gearbox mount bolts into frame before you let gearbox rest on the mounts.
Peter added a note about installing the gearbox cover/tunnel:
When I reinstalled mine, the hole for the shift lever was too far back and prevented me from engaging first completely. Eventually, the car started jumping out of first. I just finished replacing first gear and my laygear to correct the problem.
This time I took careful measurements before I put the cover on the gearbox to make certain that I would know exactly where the shift lever was when first gear was fully engaged.
Please send comments, additions, and errors for the SOL Healey web pages to Bob Haskell.
[SOL
Web
][
Scions of Lucas
Home Page
][
SOL British Car Clubs Page
]