[xj40] steering rack compatability


(Nigel Snowden) #1

I need to replace my rack on the 88 - I have managed to
source a brand new unopened rack from a later version (for
the 2.9, 3.2 or 4 litres)
The fittings and mountings all look exactly the same but
they obviously have different part numbers

Mine is MMA3890AA, the new one is MMB 3890AA - does anyone
out there know of any reason why I cannot fit this new rack
to mine ?

personally cannot see why not however decided to refer to
the massive knowledge base we have on this site

Thanks in advance

Nigel–
1987 XJ40 3.6 Auto Sov SAJJHALH3AA512874
Singapore, Singapore
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !


(Jaguarpete) #2

In reply to a message from Nigel Snowden sent Thu 20 Aug 2015:

I tried and failed trying to fit a 94 rack into my 88.
Although the body of the rack and all fittings will match,
the pinion shaft is a bit shorter on the newer racks and the
88 steering shaft won’t reach. If you can source a matching
damper and lower shaft, I think the upper shafts are the
same. The parts drawings suggests there may be some
adjustment available, but I wasn’t prepared to make a huge
project out of it.
Luckily, I found a guy on the West coast who was trying to
fit an 88 rack into a 94, so we swapped racks.–
Pete Peterson 70E(193K) XJ40s(88-270K,89-97K, 94-122K)
Severna Park, Maryland, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !


(Nigel Snowden) #3

In reply to a message from Jaguarpete sent Fri 21 Aug 2015:

Pete

Thanks that advice - the pinion shaft is actually the same
length as my original HOWEVER the groove for locking bolt
is lower on the shaft by about 3 mm

I ground out the groove a little higher on the shaft and it
then fit

Will test it out tomorrow

Nigel–
1987 XJ40 3.6 Auto Sov SAJJHALH3AA512874
Singapore, Singapore
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !


(John Quilter) #4

In reply to a message from Nigel Snowden sent Sat 22 Aug 2015:

Keep in mind that sometime around 1992, if I recall
correctly, Jaguar shifted suppliers from Adwest to ZF since
they were having continual warranty issues with Adwest racks
and Adwest, in spite of repeated attempts at reengineering
the units, was unable to meet Jaguar quality and durability
standards. ZF then designed a replacement rack and from
that point forward all OE replacement racks and ones fitted
to new cars, were of ZF manufacture and were far superior.
They also made them for the XJS range which have the three
bushing mounting design. When I converted my 1965 3.8S to a
rack and pinion I specified a ZF rack from an XJS.–
The original message included these comments:

Thanks that advice - the pinion shaft is actually the same
length as my original HOWEVER the groove for locking bolt
is lower on the shaft by about 3 mm
I ground out the groove a little higher on the shaft and it
then fit


John Quilter 1965 3.8S, 1951 MGTD, 1960 Morris ,1990 XJ6
Eugene, Oregon, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !


(Bryan N) #5

In reply to a message from Nigel Snowden sent Thu 20 Aug 2015:

Nigel,

I’m a little late coming to this party, but I’ve just
recalled that there was a minor but perhaps significant(?)
change to the steering rack introduced on the '93 and on
models which makes them differ from the earlier car racks.

For the '93 MY on they altered the steering rack pinion
angle by rotating the rack 10.5� horizontally towards the
rear which obviously alters its relationship to the
universal joint to which it connects.

The replacement rack you have obtained, MMB3890AAN, was
first fitted in the '93 MY so it will have the modified
pinion angle. I’m not sure what if any that will affect its
fitment to or operation in your '88 car.–
The original message included these comments:

I need to replace my rack on the 88 - I have managed to
source a brand new unopened rack from a later version (for
the 2.9, 3.2 or 4 litres)
The fittings and mountings all look exactly the same but
they obviously have different part numbers
Mine is MMA3890AA, the new one is MMB 3890AA - does anyone
out there know of any reason why I cannot fit this new rack
to mine ?


Bryan N, now Jag-less, but fun while it lasted.
Cambridgeshire, United Kingdom
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !


(Nigel Snowden) #6

In reply to a message from Bryan N sent Tue 25 Aug 2015:

Bryan

As usual you have information that no one else has ! - that
would explain why, even though I can connect, the universal
joint is a little ‘strained’ and the steering is binding
when certain angles of the joint are reached

I need to extend the lower shaft by a little bit - I will
try to remove this link and then take to workshop and
extend a little - don’t suppose you have any ideas how
much ?

Thanks again - now I know what the problem is (I really
could not understand what the problem was as I measured and
compared with the old rack and all seemed to be ok - I did
not however notice the shift in the angular relationship)
I suppose they must have had a good reason for doing that ?

Nigel–
1987 XJ40 3.6 Auto Sov SAJJHALH3AA512874
Singapore, Singapore
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !


(Bryan N) #7

In reply to a message from Nigel Snowden sent Thu 27 Aug 2015:

Nigel,

I am guessing, but I believe it had something to do with the
introduction of the driver side airbag on the '93 model. I
think that required an alteration in the
mounting/geometry(?) of the steering column so, quote,:-

‘‘The change allows the upper and lower universal joint
angles to more closely match, providing smoother steering.’’

BTW, they also increased the cross sectional area of the
piston and barrel in the new rack you obtained ‘‘In order to
reduce steering effort whilst parking.’’

I don’t know of an easy solution to compensate for the new
pinion shaft angle when fitted to an older car. Is it
possible to pack one side of the rack mounting flange to
‘tilt’ it back that 10.5 degrees to better align with the
original universal joint?–
The original message included these comments:

As usual you have information that no one else has ! - that
would explain why, even though I can connect, the universal
joint is a little ‘strained’ and the steering is binding
when certain angles of the joint are reached
I suppose they must have had a good reason for doing that ?


Bryan N, now Jag-less, but fun while it lasted.
Cambridgeshire, United Kingdom
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !


(Nigel Snowden) #8

In reply to a message from Bryan N sent Thu 27 Aug 2015:

Bryan

It actually looks like they tilted it a little forward (not
rear) as the lower column is now not long enough - the
joint is at max extension when at rest - I will remove the
lower column and lengthen it a bit in the workshop with a
small extension and see if that works

Can I remove the lower link without dismantling the whole
car ? - ie can I get at the top clamp from under the dash ?

Nigel–
1987 XJ40 3.6 Auto Sov SAJJHALH3AA512874
Singapore, Singapore
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !


(Bryan N) #9

In reply to a message from Nigel Snowden sent Fri 28 Aug 2015:

Nigel,

That’s odd.

I’ve checked the wording in the description of the changes
introduced for the '93 model and it says:-

‘‘The steering rack pinion angle is changed by rotating the
rack 10.5 degrees to the horizontal (toward the rear of the
vehicle)’’

I’ve never removed a steering column so I can only go on
what it says in the FSM - but it looks fairly straightforward.

With the steering wheel dead central, key removed, from
under the dash you need to slide up the plastic cover over
the U/J connecting the lower to the upper column and
disconnect from it the lower column.

From inside the engine bay you disconnect the U/J from the
pinion shaft ‘‘noting the position of the clamp hole’’ (so
that must be important).
That apparently allows you to withdraw the lower column
through the floor - making sure you retrieve the plastic
collar/spring thingy from inside the car.–
The original message included these comments:
It actually looks like they tilted it a little forward (not
rear) as the lower column is now not long enough - the
joint is at max extension when at rest - I will remove the
lower column and lengthen it a bit in the workshop with a
small extension and see if that works
Can I remove the lower link without dismantling the whole
car ? - ie can I get at the top clamp from under the dash ?


Bryan N, now Jag-less, but fun while it lasted.
Cambridgeshire, United Kingdom
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !


(Nigel Snowden) #10

In reply to a message from Bryan N sent Fri 28 Aug 2015:

Bryan

Many thanks - yes its does sound a little strange - once I
have it removed then will see what is what - especially
interested in your very technical description ‘thingy’!!

Its definitely to short at the moment - probably about half
to one centimetre

Thanks for the assist

Nigel****************************************


1987 XJ40 3.6 Auto Sov SAJJHALH3AA512874
Singapore, Singapore
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !


(Nigel Snowden) #11

In reply to a message from Nigel Snowden sent Fri 28 Aug 2015:

Bryan

Update - OK it was as you advised very straight forward -
took about 20 minutes - to remove the lower column
The ‘springy thingy’ had, over the years, disintegrated and
not very much left - trying to get that new I think is a
problem so may have to jury rig something later

When I undid the top of the damper joint there is about 1
centimeter adjustment available on the clamp so am hoping
that will be enough to get me to where I need to be - I
think the new rack configuration may be resulting in the
lower arm coming into contact with the edge of the opening
when its turning so will be checking that before tightening
everything up again - may need to open up the hole for the
column a little bit

Will update later

Thanks for the assist and if you happen to have a ‘thingy’
(part number CBC6080 and CBC6078) anywhere then please let
me know !

Nigel–
1987 XJ40 3.6 Auto Sov SAJJHALH3AA512874
Singapore, Singapore
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !


(Jaguarpete) #12

In reply to a message from Nigel Snowden sent Sat 29 Aug 2015:

That looks like a rubber gaiter of some sort. E-mail the
folks at Welsh Enterprises (www.welshent.com) I’ll bet they
have a bin full of them. They have a Yuuge inventory of old
Jag parts.–
The original message included these comments:

Thanks for the assist and if you happen to have a ‘thingy’
(part number CBC6080 and CBC6078) anywhere then please let
me know !


Pete Peterson 70E(193K) XJ40s(88-270K,89-97K, 94-122K)
Severna Park, Maryland, United States
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !


(Nigel Snowden) #13

In reply to a message from Jaguarpete sent Sun 30 Aug 2015:

Pete

Nobody has this thingy - have tried everywhere - think I
will jury rig something from the rubber gaitors that are
used at the ends of the steering racks

If anyone does have a thingy then please let me know !!

Nigel***********************


1987 XJ40 3.6 Auto Sov SAJJHALH3AA512874
Singapore, Singapore
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !


(Nigel Snowden) #14

In reply to a message from Bryan N sent Tue 25 Aug 2015:

Bryan

Update - OK the lower column has enough adjustment on the
spline where it connects to the upper universal joint
arrangement to take account of the later rack - its
actually a simple adjustment (now that I have done it,
isn’t hindsight a wonderful thing ?)

The only thing I am still worried about is that now I don’t
have the ‘thingy’ which I cannot source anywhere so if it
rains I will undoubtedly get water ingress into the
footwell - tried jury rigging something with the rubber
gaiter off steering rack and does not work as the outer
housing is at an angle to the inner shell - I will probably
pack it with some foam as a temporary measure until I can
find a thingy !

So if anyone is trying to fit a 94 rack to an 88 just tell
them to contact me - its not difficult - the offset is
definitely NOT to the rear - had to take the adjustment out
towards the rack ?

The adjustment is on the spline secure clamp - the spline
groove is about 10-15 mm long so my original was at its
shortest (towards the steering wheel) and now is towards
the maximum away from the steering wheel

Thanks for the assist

Nigel–
1987 XJ40 3.6 Auto Sov SAJJHALH3AA512874
Singapore, Singapore
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
–Support Jag-lovers - Donate at http://www.jag-lovers.org/donate04.php

Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !


(2tonejag 1989 XJ6 XJ40) #15

Nigel I realize this is an old POST but found part in Germany???
https://www.carparts-pros.com/page_1_3.php#oeformo
in sub for above rubber gator could you use a power steering rack rubber bellows? or a rubber shift boot-bellows and or could you carefully spray in some (SOFT NON EXPANDING URETHANE FOAM??)
Anyway just a thought and this is probably the source of a minor air leak in my 89 XJ6 steering column only noticeable when cold air comes in the winter.
Brad in NY LI