Can anyone help please:
The 6 litre factory XJR-S had a GM400 gearbox part number: SPE1027
https://www.jaguarclassicparts.com/u...ic-jaguarsport


Ordinary 6 litres had a 4 speed box, I believe. My question is as follows:
Does the GM400 part number SPE1027, as used in the factory JaguarSport 6 litre cars have the same bolt pattern as the 5.3 litre V12 engines, or does it have the later bolt pattern as used on the 4 speed boxes on facelift cars?


Thanks in advance for any help anyone can give.

 

same as the 5.3 litre engines Greg. The change came with the 4L80E gearbox. If the car has the three speed it has the earlier bolt pattern.

 

Thank you very much Baxtor. Just what I needed to know.
Greg

 

Just to add my 2c worth.

Baxtor is correct all Jaguar 5.3L HE's and TWR 6.0 and 6.1L that used the TH400 had the same bolt pattern. This bolt pattern was also used by Jeep.

The Jaguar 6.0L and 4speed auto had a different bolt pattern that was also used by Rolls Royce, I have not been able to find any other info on this bellhousing.

The Jaguar 6.0L block still has the pads for the TH400 but these are not drilled. So a TH400 can be bolted to a later 6.0L block without an adapter. But a Jaguar 4L80 can not be bolted to a 5.3L without an adapter.

 

The Jaguar 5.3L with lip seal has the pads for the 4L80E. With rope seal was for the TH400 only.

 

So the change was somewhat around 1988/1989?

 

Warren can you comment on this, l know your 5.3 is lip seal. I have never seen the layout described and know the change to lip seal was in 89 but gearbox change was several model years later.
I would have to see it to believe it as it makes no sense to make provision on a production motor for a gearbox change some years ahead of the actual changeover.

 

My 1989 Lip seal 5.3L does not have 4L80e pads on the block. I know this for certain as I replaced the transmission a couple of months ago.

 

I will post a picture asap.

 

That is what I was thinking. Around my bell housing are no extra pads or areas you could use to fit a different tranny. They are basically as round and the same shape as the TH400 - and that on an 89 lip seal block...

 

Here is a pic of the back of my 5.3L, it's not very good as the shed door was up. I do not have a pic of the back of 6.0L.

.

 

that pic does have the early bosses for the 400 trans! jag used GM's chevy pilot dowel location, been on chevy blocks since 1955, all 4 cylinder,inline 6 cyl, V6 ,and all V8 till some LS and newer LT blocks.

and its the same as my 1978 5.3 block, that i used to center the 700 trans to the center of the crankshaft!, i used a Chevy 700 truck trans with an adapter plate for chevy to the round Jag bolt pattern , had to drill counter sink socket head bolts into the jag block!

must work been that way for 22years , and still runs great!

 

I drilled and tapped the TH400 bosses on my 6.0 Litre as I was unsure I could fit the 4L80E into my '89 and it gave me both gearbox to motor options. In the end went with the 4L80E.
I did take pics but unfortunately am missing that sd card.

 

My 6.0L block is also drilled for the TH400 so when I swap engines the 4L60e will bolt up directly with the adapter I already have.

Yep Ron I used the V12 dowel pins to line up the 4L60 then made longer pins

 

5.3 with rope



5.3 with lip

 

My 5.3l with lip seal looks different.

 

Here we go, a 1989 lip seal rear end



No possibility to bolt on a later 4 speed slush box!

 

Not the best angle but it is the back of a 6.0ltr engine.

Rgds.

A.

 

Very interesting. Now I've seen it l believe it.
What is engine number. I suspect it is within very few numbers of change to new gearbox.

 

According to JDHT the part number changed to EBC3026 at engine number 83212 and stayed the same through the 6.0L block. Makes you wonder WHY Jaguar would make a change to the block years before upgrading to the 4speed auto.