DarrenW
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| posted on 28/4/06 at 11:22 PM |
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Gearbox oil loss - 1.5.06 investigation
Im losing gearbox oil. 'Box is std sierra type 9. Had to top the box up tonight (to correct level just below the side filler screw). I cant suss
out where in losing the oil from. I have checked the seal where the prop fits (at the nose) and this is bone dry. The screw where you fil up is also
bone dry. I recall before fitting the box that the inside of bellhousing area was right sh1tty.
Q - where is the most likely place where the gearbox will leak and how easy is it to fix? Ill check that area first.
Thanks,
darren
[Edited on 30/4/06 by DarrenW]
[Edited on 1/5/06 by DarrenW]
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Dusty
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| posted on 29/4/06 at 12:13 AM |
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Favourite places are the paper gasket between the front of the box and the plate that locates the input shaft seal cover but also covers the selector
shaft holes. The input shaft seal can also leak this end. Both coat the inside of the bellhousing with black oil and eventualy the clutch. Also can
leak at the speedo takeoff.
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dave r
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| posted on 29/4/06 at 07:48 AM |
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i remember replacing the front seal on mine when i built it cos it leaked... made a new paper gasket, and it leaked from that!
the paper has to be thick enough, or the circlip in the front bearing bottms out before the gasket does
i didnt swear much 
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DarrenW
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| posted on 30/4/06 at 08:44 PM |
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Ok - time to get serious. Just got back from Stoneleigh. 200 miles each way. Topped up the gearbox before setting off and found the oil all over floor
when i got there. Topped up with 250 mls when i got there and again was swimming in the bloody stuff by the time i got home.
Q1. Ive checked Haynes manual - total crap, ne decent schematics and hints on where the seals and gaskets are. Does anyone have a good link to a site
that explains how to replace the seals.
Q2. Ive already repleced the rear oil seal (where prop fits). My gearbox sits further back than a std locost etc. Reason oil is all over the floor
foot wells is cos the ali floor goes under the tranny tunnel area and oil is dripping onto this bit and running along into footwell area. Bellhousing
seems to be free of oil. Where is most likely place for oil to be leaking?
Q3. Digidash uses prop magnets for speed. Ive not used the gearbox drive. If no cable if fitted will the oil p1ss out of a hole!!! ie do i have to
block off this bit if not fitting the speedo drive?
Please help with some pics / schematics / stroks of wisdom. Ive ruined a pair of trousers and trainers with oil so really should fix!!
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DarrenW
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| posted on 30/4/06 at 10:32 PM |
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Mmmmmm - i agree Chris. It just dawned on me today whilst trying to ave ruined trousers that i may have made a dumb mistake. Problem is i dont even
know if there is a hole to plug and cant find any suitable links etc to explain if my suspicions are correct.
Im hoping i dont have to take engine out to fix!
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NS Dev
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| posted on 1/5/06 at 11:03 AM |
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I asked about plugging the speedo drive hole but was told it was ok, no need to. It looks like the seal in there seals against the plastic gear bit,
so oil can't get out cable or no cable.
The seals it can leak though are:
1) Rear seal (you've done it already)
2) Front seal, pushes into the rear of the trumpet housing on the front of the 'box. Take off the box and remove the 4 10mm bolts holding it on
and replace the seal.
3) Gasket between 'box and bellhousing. This seals the gear selector shaft. Doesn't need to be a gasket, silicone works ok in here.
4) speedo drive seal. There's a small rubber seal in the speedo drive, this may have worn out?
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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jos
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| posted on 1/5/06 at 11:14 AM |
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My first thought was speedo drive hole too
.: Motorsport / motor racing circuit / track wall art Apex Traxs :.
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DarrenW
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| posted on 1/5/06 at 05:08 PM |
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quote:
Originally posted by NS Dev
I asked about plugging the speedo drive hole but was told it was ok, no need to. It looks like the seal in there seals against the plastic gear bit,
so oil can't get out cable or no cable.
The seals it can leak though are:
1) Rear seal (you've done it already)
2) Front seal, pushes into the rear of the trumpet housing on the front of the 'box. Take off the box and remove the 4 10mm bolts holding it on
and replace the seal.
3) Gasket between 'box and bellhousing. This seals the gear selector shaft. Doesn't need to be a gasket, silicone works ok in here.
4) speedo drive seal. There's a small rubber seal in the speedo drive, this may have worn out?
Thanks Nat. Nice list to work with. Im trying to deduce which would be the most likely from where i know the oil is dropping to. Bearing in mind that
my engine and box sit further back (i dont need a gear selector extension). The oil is dripping doen to the floor pan bit under the transmission
tunnel then running into the cockpit. Im kind of guessing that no.3 above is a likely culprit or perhaps no.4. If this is the case (ill take panels
off and take a look) im guessing i can effect a teparary repair with some bond and seal or similar until i next take the engine out.
If no. 2 is faulty would thid tend to leak the oil into bellhousing area nd drip out of the bottom? (Im not discounting this at present cos if it is
pumping out of here the wind under car would carry the oil back to the floor.)
Thanks for all the advice - time to get a good look at it.
I dont suppose anyone has some good picks of seal replacements in their photo archive do they?
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rusty nuts
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| posted on 1/5/06 at 05:21 PM |
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Could also be leaking from the rear housing to main casing gasket. Try cleaning the area, top up and take for a short drive . Then recheck , you may
be able to see where it's leaking. I find brake cleaner in a pump up spray works well for cleaning .
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DarrenW
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| posted on 1/5/06 at 09:24 PM |
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Ok. ive stripped the interior side panels out etc nad had a good look. Ive also looked at the pics that Guinness posted carefully.
Does this sound right???
* Gearbox casing has a cover on top held with 10 short 10mm hex bolts. Gasket still present - no oil loss seen from here.
* In front is the bellhousing. Ive examined inside where clutch arm is - clutch and flywheel is dry. I levered steel cover plate back and whilst its a
touch oily inside there isnt copious qty's of oil in there and certainly no drips observed from bottom of bell housing. I suspect oil is engine
oil from the slightly leaky sump that came as std on all Pinto#s.
* Behind the gearbox casing is what looks like a 20mm ish spacer plate. Behind this is the part that the output shafts run in and selectors are on
top. I assume there should be 2 gaskets here (1 either side of the plate). Bolts seem tight but oil splatter seems to start approx at this point. Oil
seems to have been flung onto the side of the interior panel more on drivers side, run down and leaked thro to floor.
* To the bottom of the rear casing is the speedo drive. No speedo cable is fitted. I cant be sure if oil has been coming out of this.
* at the back of the gearbox the output shaft exit and prop slides onto splines. I have replaced the rear oil seal and this continues to be dry.
* When oil is thrashing around in main casing, especially at motorway speeds will this cause positive pressure that will force oil out of the rear
gaskets? Is it likely that the oil wont be lost when car is parked up?
I filled box on Saturday night (by taking top plate off and filling to the bottom of the filler screw - not above). At Stoneleigh i had to add 250ml.
You can imagine what 500mils of gearbox oil looks like as its splattered under car, along inside of tranny tunnel and all over bach chassis etc!!!!
Yuck - not nice. Rags soaked in panel wipe thinners is cleaning it up.
im considering 2 temp repairs:
1. Clean off the sandwich plate behind main casing (toothbrush and panel wipe) and cover the joins externally with bond and seal.
2. Cover the speedo drive outlet with a suitable plastic cover and seal with bond and seal.
Any comments?
Thanks again.
[Edited on 1/5/06 by DarrenW]
[Edited on 1/5/06 by DarrenW]
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MikeRJ
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| posted on 1/5/06 at 10:29 PM |
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quote:
Originally posted by DarrenW
Any comments?
A pictures tells a thousand words...
If you have a digicam would be worth taking a few pics to stick up in here.
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DarrenW
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| posted on 1/5/06 at 10:38 PM |
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Yeah - sorry for length of post.Im trying to provide sufficient data to get good answer.
Dont have any diagrams yet. There is a photo in my other thread (ref Type 9 pice request).
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NS Dev
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| posted on 2/5/06 at 09:30 AM |
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I'd find it very unlikely that the gaskets either side of the 5th gear sandwich plate (the inch thick ally bit on the back of the main box
casing) are leaking, unless the bolts have come loose.
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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DarrenW
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| posted on 2/5/06 at 10:06 AM |
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Bolts are tight (checked them last night). I wonder if the oil may be coming from speedo drive connection. I guess this would chuck the oil about as
well. Most of the oil is observed from the drivers side but due to motorway speeds it was quite messy under there. Ive found a cap that i can bond in
place toseal it off.
I had same thoughts about the gaskets hence why i asked if this could be forced through under pressure (assuming pressure is provided when the gearbox
is operating at speed).
Ive got front of car high in the air. Oil level is low at present but i didnt see any natural leakage this morning. Bit of a puzzler. Ill try the bond
and seal idea as a temp repair.
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NS Dev
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| posted on 2/5/06 at 11:26 AM |
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If it is coming from the speedo drive then when the box is out in the future it wants a new seal on it. It's a tiny little thing that pushes
in.
There's a chap on ebay that I have used a few times and is VERY good. his user name is "bearings!" and he has an ebay shop. Does all
sorts of gearboxy and gaskety things that are very useful indeed.
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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DarrenW
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| posted on 2/5/06 at 11:41 AM |
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Cheers Nat - i found him last night. he has loads of good bits. Im hoping i can get way with not lifting the box out for now. I just want to have some
fun driving it!!!!! How lazy is that??? I have a sneaky feeling that i will end up taking it all out, and as daft as it sounds should only be a few
nights work midweek. Ill probs get an uprated mount as well some time.
I have noticed that my box finds its own level then doesnt leak as much........ unfortunately that is when there isnt much left!! maybe i need a
self recirculating catch tank system............
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CairB
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| posted on 2/5/06 at 09:32 PM |
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DarrenW,
Don't know if it helps but I've been diagnosing a slow leak from my type 9 box tonight. To help trace it I removed the M12 socket grub
screw from the upper passenger side of the box, it retains a spring, and fitted an M12 bolt with a hole through it that I could pressurise the box
with an air supply, less than 5psi. I then found that the drip frequency increased from under the box and appears to be coming from the front face so
it looks like tomorrow night is an engine out job. I believe that this pressure should be ok as the shafts are stationary.
I also had a look at the front seal housing on a spare box. The front bearing retaining circlip is about 2mm thick and the recess in the front housing
is around 1.35mm so it looks like the gasket thickness is fairly critical to ensure a seal but allow the flange to clamp the circlip. Another problem
could be if the flange bolts aren't tightened evenly as this could cause tilting of the flange and another leak path.
Fixed your leak yet?
Cheers,
Colin
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DarrenW
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| posted on 2/5/06 at 11:01 PM |
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Well well well....
Looks like i might have fixed it.
I cleaned the box tonight. Refilled and replaced cover plate. Lifted back wheel up and ran the car for few minutes. Would you believe it - small hole
in the rear gasket between main casing and the rear housing. While 'box is running the oil in the main case creates a positive pressure - i
could then see the oil coming from a small hole in the top.
Further cleaning, wire brushing, cleaning, cleaning and some acetone for good measure and a managed to give the culprit area a right good clean. I
then applied some JB Quick weld around the area plus a bit more and after an hour ran the car again. This time in 4th at approx 50mph for about 5 mins
= no leak.
Ill do an extended run tomorrow with the interior panels off for extended test.
Speedo drive was dry and remained dry.
Ill report back in a while.
Thanks all for help.
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NS Dev
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| posted on 3/5/06 at 10:27 AM |
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well there you go, so much for my advice
sod's law!
Glad it sounds like you've cracked it!
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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DarrenW
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| posted on 3/5/06 at 10:34 AM |
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quote:
Originally posted by NS Dev
well there you go, so much for my advice
sod's law!
Glad it sounds like you've cracked it!
I hope i havent cracked it!!!! I drove the car to work with all of the covers off and seemed to be fine. Ive had some good experiences using JB
weld for temp repairs. Another job for my winter project list.
its just typical that the bits i havent touched have failed me. And to top it all failing in the least expected places (core plug behind bell housing,
dizzy cap and now this leak. At least my engineering is proving to be robust.
Thanks again.
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