Main shaft LT77 gearbox question

Beans · Postby **Beans** » 12 Feb 2012 13:24

I have at last started on the new gearbox for my DHC (LT77/5 speed â€˜box).
But while checking the new mainshaft I have ordered against the old one,
I noticed that the lubricating holes for the gears were different.

On closer inspection it turned out that both the old and the new shaft have the same diameter holes (Ã¸2mm).
But on the old shaft the diameter of these holes has been reduced to a little over Ã¸1mm by fitting thin spring dowels.
The new shaft doesn't have these dowels fitted.

So what to do? Fit dowels to the new shaft (already found a supplier) or leave it as is.
The last option will probably result in more oil for the gears and less for the rear bearing of the input shaft.
(b.t.w. the main oil galley (inside of shaft) has a diameter of Â± Ã¸8mm).

Your opinions please [:)]

<center>

1980 TR7 DHC (my first car, now restored and back on the road)
1981 TR7 FHC Sprint (better known as 't Kreng)
[url="http://www.tr7beans.blogspot.com/"]My Weblog[/url]</center>

john 215 · Postby **john 215** » 12 Feb 2012 19:43

Hi Beans,

Intresting one, maybe the dowels were fitted provide a restriction to control oil flow around the gearbox, seen similar on engine blocks to control oil flow to the cylinder head ( Rover 'S' series ) and then they decided they were not needed [?]

May be worth dropping these guys a email, very good with LT 77 boxes mainly 4 x 4 but basically the same as you know.

http://www.ashcroft-transmissions.co.uk/

Cheers John

LIVE LIFE A QUARTER OF A MILE AT A TIME!

1976 Speke FHC Beauty

1979 3.5 FHC(STATUS PENDING!!)

1982 2.0 DHC NOW A 4.6,ON THE ROAD NOW KICKING AR5E !!!!

Workshop Help · Postby **Workshop Help** » 12 Feb 2012 19:58

The one bearing in a LT77 gearbox most in need of oil is the needle bearing inside the back of the input shaft that supports the front end of the main shaft. The excess oil is then spewed/splashed onto the input shaft to lay shaft gears.

The first question will be; does the restriction pass enough oil to sufficiently oil the needle bearing and then the input gear to lay shaft gear? The second question will be; is this restriction in flow intended for use in another LT77 gearbox aimed at commercial or off road or military vehicles use rather than our sporting vehicles?

Mildred Hargis

Beans · Postby **Beans** » 12 Feb 2012 21:32

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by john 215

... maybe the dowels were fitted provide a restriction to control oil flow around the gearbox ... <hr height="1" noshade id="quote"></blockquote id="quote">
Yes, it indeed looks like an afterthought,
maybe they did fit them when they decided to change to the thinner automatic gear oil?

Or did they lack the proper diameter drills at BL [:D]

<center>

1980 TR7 DHC (my first car, now restored and back on the road)
1981 TR7 FHC Sprint (better known as 't Kreng)
[url="http://www.tr7beans.blogspot.com/"]My Weblog[/url]</center>

Shauniedawn · Postby **Shauniedawn** » 12 Feb 2012 22:18

The last LT77 I did was for my Land Rover. That didn't have them in. But the LT77 I did off the TR7 did. You can see the insert in the photo below.

Have a look at this photo - the TR7 mainshaft is in the middle. Worn Land Rover shaft in the front of the picture, new to the rear.

[img][IMG]http://i422.photobucket.com/albums/pp305/shauniedawn/LT77%20Gearbox%20Overhaul/DSC_8539.jpg[/img][/img]

And another of just the new and old LR shafts:

[img][IMG]http://i422.photobucket.com/albums/pp305/shauniedawn/LT77%20Gearbox%20Overhaul/DSC_8449.jpg[/img][/img]

Sorry - that didn't really answer your question though! I'd ask Ashcroft as John suggests.

Shaun

Beans · Postby **Beans** » 12 Feb 2012 22:29

So by the looks of it Land Rover enlarged the holes !?

But I will send an e-mail to Ashcroft, thx so far [;)]

<center>

1980 TR7 DHC (my first car, now restored and back on the road)
1981 TR7 FHC Sprint (better known as 't Kreng)
[url="http://www.tr7beans.blogspot.com/"]My Weblog[/url]</center>

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Main shaft LT77 gearbox question

Main shaft LT77 gearbox question

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