Gearbox swapping at home - the pitfalls

[Wayne S]

Hi All,

I'm in need of replacing the gearbox in the TR over the winter along with the clutch. Now... I'm stupidly feeling quite keen to do it myself at home.

Has anyone done this just on the garage floor with the aid of ramps and the odd jack here and there? What are the pitfalls? Can anyone run it through step by step from their own experiences or is it one of those where its just more sensible to get a nice man in a garage with a four post lift to do it for you?

Am I being a wimp basically?? lol

<b>Red 4.0 Litre V8 DHC Grinnall (with huuuuuge arches...!)</b>

[Workshop Help]

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Yes, I did the conversion from the four speed to the five speed on my back, on the concrete floor of the machine shed, using car ramps and concrete blocks, and a garage floor jack with the help from a lovely assistant to muscle the lump back into place, after I personally overhauled it. Whew! That was one long sentence!

Are you a wimp? That's not for me to say.

Can you do it, too? That's up to you.

Were I you, I'd start by doing a whole lot of reading before the car gets jacked into the air. As for the typical garage mechanics abilities, the less I opine, the lower my blood pressure stays.

Mildred Hargis

[Jolyon39]

Hi,

I put the car up on 4 ramps, one for each wheel.

Took off the prop shaft gearstick etc... Leave the rear gearbox mount for a moment

Then I undid all the bell housing bolts (there are a lot)

Now place a lump of wood behind the head so the engine will rest against this and not swing down too much when you remove the gearbox mount

Now.... a small trolley jack under the gearbox mount and another for casing. Pry the Bell housing away from the engine and wheel back with the jacks. lower it down and drag it out from under the car.

Reinstalling with two trolley jacks allows you to get it lined up at the perfect angle and then roll forward into the engine. (i seem to recall that I ended up cupping the bell housing and engine plate together in the front jack cup that makes contact with things being lifted. The front jack was in this case a very large jack.)

honestly, the two jacks made it easy for me.

Jolyon

[Hasbeen]

Yes, what they said.

I don't know about Jolyons 2 jack system, I'd have to think about it, & look at how it would work, but you must be able to support the box on a jack, with total security. Using 2 just might be the trick.

The first time I did one, I had the front on 11" ramps, & stands at the back. A little higher would be better. I pulled the box out as I had others in the past, & found myself under the thing, with the box on my chest, & I was not strong enough to lift it off me, in that position.

It took what seemed like a long time to get out of there. I then made a timber cradle to fit the big floor jack, & support the box & bell housing very securely.

Do be careful of the fuel & brake pipes in the tunnel when refitting the thing.

The second time, I used a mates high ramps, with over 4 Ft clearance under the box. With some help this time, up there it was easy. The only bother was climbing up on to the ramps to work, then back down underneath all day.

Hasbeen

[Beans]

I have done them all, low ramps, lift or inspection pit.
I still prefer the latter one.
You can access the engine compartment from above and below and the car is as stable as can be.
Also with a pit you can use all kinds of supports to make life easier.

Bear in mind the bl**dy thing weighs well over 50 kg’s

<center>
<font color="blue"><i>1980 TR7 DHC (my first car, now restored and back on the road)
1981 TR7 FHC Sprint (better known as 't Kreng)</font id="blue">
<b>[url="http://www.tr7beans.blogspot.com/"]<u><b><font size="2"><font color="red">My Weblog</font id="red"></font id="size2"></b></u>[/url]</b></i></center>

[REPLIC8]

I did mine with the front wheels on ramps & the back up on high stands. I also used Jolyon's two trolley jack method. With a willing assistant it's a pretty straight forward job. I laid a length of 4x2 timber across the engine bay and used ratchet straps over it to support the weight of the rear of the engine to stop it twisting on the front mounts.I found the worst bit was splitting the exhaust joints, once that's done it's just a methodical nut & bolt job.

Andy
1981 UK SPEC TR8
[img][IMG]http://i473.photobucket.com/albums/rr92/REPLIC8-2008/175-1.jpg[/img][/img] [img][IMG]http://i473.photobucket.com/albums/rr92/REPLIC8-2008/pics005.jpg[/img][/img]

[darrellw]

Not sure if you have an equivalent to Habor Freight in the UK, but I would seriously consider buying, borrowing or renting a transmission jack. It will give you a much more stable platform for maneuvering the transmission around. Something like this:

http://www.harborfreight.com/automotive ... 39178.html

Darrell Walker
66 TR4A IRS-SC CTC67956L
81 TR8 SATPZ458XBA406206
Vancouver, WA, USA

[saabfast]

As above, it is possible in many ways. I did it on my own in the garage. Recommend a course of weightlifting first, it is VERY heavy for a gearbox. I had it on axle stands on blocks of rail sleeper front & back to get it high enough. Made a small timber 'tray' to sit on a trolley jack and fit under the box to help keep it squarish ( I think this was Clays idea). It took a lot of levering with a jemmy to separate from the engine as the dowels were very tight but then falls out as the engine is tilted back.

I used two trolley jacks (and at times a scissor jack)to put it back as it has to go in at an angle to match the tilt of the engine and slide forward. Once it was close to in I used clamps to pull it right up to the engine, seemed a bit difficult by hand.

Good luck!

Alan
Saab 9000 Stg 1
Saab 9000 2.3 FPT Auto
'81 TR7 DHC

[Stag76]

I've got a 2-post hoist, and I made a table that attaches to an engine crane and can be tipped forwards or backwards. I attached the box to the table using straps. If you can get access to a hoist, it makes the job a lot easier, even little things like undoing the bell-housing bolts etc. If you are fitting a new clutch, it's worthwhile removing the flywheel and having it faced.

TR7 Convertible
Sprint Motor
MegaSquirt EFI

[davesopener]

hi wayne,
2 questions.
Is the gearbox shot?
Are you thinking of an alternative gearbox?
dave

[Chunk]

Have used 2 trolley jack method many times in single garage.
A medium to large one fits under bell housing nicely.
I remove gearbox cross member and then drop gearbox down.
A piece of wood between engine and bulkhead is good.
Tial and error on size required.
Then you can get to bell housing bolts easier underneath and remove flywheel cover plate.
The tubular exhaust manifolds need to come off if fitted, aswell as the whole exhaust (rally in my case).
Worth checking rear crank seal while gearbox is out.
Can be done in a day. Better to take time and check and clean everything.
P.S. Best to remove gearlever aswell.
P.P.S. Clutch fork can wear on pivot.

1979 TR7V8 FHC.
DJE 4.6 Block and Heads.
22 years of tinkering and tuning......So far!
Now available in red.

[FI Spyder]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by darrellw</i>


Not sure if you have an equivalent to Habor Freight in the UK, but I would seriously consider buying, borrowing or renting a transmission jack. It will give you a much more stable platform for maneuvering the transmission around. Something like this:

http://www.harborfreight.com/automotive ... 39178.html
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

I was thinking of making something like that with a scissor jack. I may check local discount tool first.



- - - - TR7 Spider - - - - - - - - 1978 Spitfire - - - - - - 1976 Spitfire - - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra - - Yellow TCT

[Workshop Help]

I believe the best 'hot tip' for reinstalling the LT77 gearbox is to install studs in the bottom two holes of the mounting plate in the same manner as the top studs. This will give a convienent target to shove the gearbox onto, thus facilitating the alignment of the input shaft with the pilot bushing.

This I will do the next time the gearbox is pulled, if ever.

Mildred Hargis

P.S.

The studs mentioned are headless bolts, not the Viagra soaked morons with more ego than equipment.

Thank you,

M.H.

[Beans]

<blockquote id="quote"><font size="1" face="Century Gothic, Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Mildred</i>

... install studs in the bottom two holes of the mounting plate in the same manner as the top studs ... <hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">
Sounds like a good tip, will try it once the gear box for DHC is rebuild [;)]

Not much progress at the moment though ...



<center>
<font color="blue"><i>1980 TR7 DHC (my first car, now restored and back on the road)
1981 TR7 FHC Sprint (better known as 't Kreng)</font id="blue">
<b>[url="http://www.tr7beans.blogspot.com/"]<u><b><font size="2"><font color="red">My Weblog</font id="red"></font id="size2"></b></u>[/url]</b></i></center>

[busheytrader]

Hi,

When I did my V8 conversion many years ago, I took the engine, clutch and gearbox out through the top with an engine crane. Once out on the garage floor it was ever so easy to change over the gearbox and renew, align and fit the clutch. Rear wheels up on ramps and deflate the front tyres for maximum clearance. It beats crawling around on the floor trying to lift heavy weights in next to no space.

All that was needed was a crane and chains plus the usual spanners etc. The car can still be wheeled in and out of the garage as it's still mobile. The hardest part was detaching the exhaust manifolds.

Adam



TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, S/S Single Pipe Exh, 3.08 Rear, 200lb Spax & PolyBushes all round, Anti- Dive, Strut-Top Roller Bearings, Capri Vented Discs & Calipers, Braided Hoses, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AT 14" 5 Spokes or Maestro Turbo 15" Alloys, Cruise Lights, S/S Heater Pipes, Replacement Fuel Tank. No Door Stickers. Mine since July 1986, V8 from 1991 courtesy of S&S V8 conversion and big brake kits.