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LT77 Gearbox Identification
Posted: Fri Sep 28, 2007 3:36 pm
Gear box identification
the identification marks can be found on an oval lug near the base of the box
G16A SD1 2000 (Could be 4 speed)
G17A SD1 2300/2600 5 speed
G19A SD1 3500 SE/VP 5 speed
G22A SD1 3500 Police spec 5 speed
G23A SD1 2600 Police spec 5 speed
G26A SD1 2400 Diesel 5 speed
G27A SD1 2000 Later model 5 speed
G28A SD1 Vitesse 5 speed
G30A Sherpa Range
Posted: Tue Jan 15, 2008 6:39 pm
Sorry about posting this in a nice tidy topic but i have what i suspect is an LT77 box, It looks the same as an LT77 i am fitting to my Manta but when i went to try and ID this box from the oval flat area by the drain plug i found that not only was the number not there but the machined area was missing too, it was just a plain casting from the factory, i can find no other numbers anywhere.
Any idea what i have here ?
Posted: Wed Feb 06, 2008 1:41 am
Is the five speed box fitted to a TR7 an LT77? If so, with the correct bell-housing, would it be compatible with a Rover V8 engine?
Posted: Wed Feb 06, 2008 1:44 pm
that what i was wondering , i have a TR7 box and sd1 bell housig and it looks like they are the same , they certainly fit together , and the TR7 clutch arm is the same as the rover one
not sure about ratio's , but as i have it all apart i'll count the teeth
Posted: Wed Feb 06, 2008 3:18 pm
with the gearbox stripped and the clusters in situe ie:the input shaft pointing sky ward
working from the top
input ............. layshaft
22 ............. 33 = 4th / pinion gear
27 ............. 29 = 3rd
32 ............. 23 = 2nd
31 ............. 14 = 1st
20 .............. 36 = 5th
and 5th gear below the plate
it has the same ratios as an SD1 V8 box
to calculate the ratio's ..first divide the pinion gear ie: 33 / 22 =1.5
then divide the input shaft by the layshaft and multiply by the 1.5 ..and thats the ratio
31 divided by 14 = 2.21 then times the 1.5 you got earlier and the result is 3.32 which is right
thankyou to Dave Ashcroft for explaining to me ... it makes sense now
or picture here : http://www.putfile.com/pic.php?img=7626912
Posted: Thu Feb 07, 2008 7:26 pm
Cheers Bodger you are a star!
Posted: Thu Feb 07, 2008 7:52 pm
Numbers stamped on the bottom of mine near where it joins the back nose casting, looking at the list it suggests its an SD1 police type. Nice !
Posted: Thu Feb 07, 2008 8:06 pm
ssshhh don't tell everyone or they will be as expensive as SD1 boxes on ebay ..lol
havin stripped the tr7 box now , all the parts are the same as an SD1 box
inc oil pump / gaskets /seals and bearings
even the rear bearing is the same , even the LDV version that is suppose to have a stronger one is the same 6205 c3 bearing
change it everytime , each box i have stripped it's always noisy
Posted: Sun Feb 17, 2008 9:15 pm
I just read the 'gearbox' section of the Haynes manual for the Rover SD1 and it states in there that the box is the same as a TR7!
Posted: Thu Oct 16, 2008 6:40 pm
Does anyone know what ratio's i have in my 'box? The serial number is 28A0011412D and want to work out what ratio diff I need for the back - once I know what size wheels are going on!!!
Posted: Thu Dec 11, 2008 7:29 pm
the only real differnence is the higher ratio 5th gear in your box TC , they all has the same ratios until the later versions ie vitesse which had a 37/19 5th gear pair
and also the sherpa version =R150-5 which had a completely differant primary ratio
Posted: Wed Nov 23, 2011 9:36 pm
I have seen a couple of SD1 manual gearboxes which I presume are LT77s, but they have a serial number like CL-044564-C.
Anyone know what these are from?
Posted: Tue Aug 27, 2013 10:51 pm
Hi. Can anyone give me any info on this box? Serial number is 28A0249247E. Thanx