fast_dave
Explorer Addict
- Joined
- June 6, 2005
- Messages
- 1,350
- Reaction score
- 756
- City, State
- East Bay - Nor Cal / PRK
- Year, Model & Trim Level
- '98 Spt 4.0 OHV 5 spd 4x4
My 98 Ex Sport 4.0 OHV has reached 203,000 Miles.
7 years / 40,000 Miles ago, due to an Anti-Freeze Leak on the Driver's Side, I replaced the Timing Cover Gasket on my 4.0 OHV, and wrote an extensive write up on it.
LINK: Removing timing cover on 4.0 OHV
History: The entire time I've owned my Ex, it has never leaked oil. To clarify, it's weeped oil, but never leaked oil to the point where it left small puddles on the garage floor.
Specific Problem: Recently, my Ex has suffered a pretty major oil leak from the Timing Cover.It drips down from the Timing Cover, and leaves small puddles of oil on the garage floor.
In short, I think the OEM FORD Green Teflon Coated Timing Cover Gasket slipped down, and allowed oil to leak.
If you look carefully at the two pictures BELOW, the chopstick is pointing to where the the oil leak is starting from. Note that the Timing Cover Gasket is not exposed past the Timing Cover. In effect, it has "sucked below" below the timing cover between the 2nd and 3rd bolt from the top Timing Cover Bolt, on the Passenger Side.
The picture BELOW shows where the Timing Cover Gasket has "bowed" outwards, within the valley that is to release Anti Freeze when your timing Cover Gasket has reached the end of it's service life. It's my feeling that that the Timing Cover Gasket gasket is bowing outwards indicates that the Timing Chain Cover and Gasket are shifting down towards the ground.
Seven years ago when I replaced the Timing Cover Gasket, there was next to no info on the internet about this procedure on a 4.0 OHV. To this day, there is still next to nothing. So I fell back on my shade tree mechanic skills/experience; First I cleaned all of the gasket mating surfaces on the block and timing cover. Since the gasket is Teflon coated, there was very little to clean on BOTH the block and the Timing Cover.
Then, I cleaned out all of the timing cover bolt holes with spray parts cleaner, chased them with a tap, and then blew out the holes with compressed air. I followed this up with cleaning all of the bolt threads with a wire brush, cleaned the threads with parts cleaner, and then wiped them down with a high-nap cotton towel.
On the five oil pan holes/bolts that mate to the bottom of the Timing Cover, all that was required was to spray clean out the five oil pan bolt holes with parts cleaner, and stick a clean Q-Tip in each hole to clean/dry it out. The five oil pan bolts were cleaned with parts cleaner, and dried off with a high-nap cotton towel.
REASSEMBLY: The reassembly was as follows. First, I installed the timing cover and timing cover gasket. I torqued them in a "star" type order like you would a wheel, so as to evenly distribute the load - i.e. bottom left, top right, top left, bottom right. I torqued all bolts in three stages, first to seven pounds, then to eleven pounds, and finally at 15 lb ft. ALL bolts were dry = no oil & no threadlock/loctite. Also, The Block sealing surface and Timing Cover sealing surface were left DRY (NO OIL) This is how the Original Engine left the factory and lasted 13 years / 165,000 Miles before the gasket failed, and anti-freeze leaked from the Timing Cover Leak Channels. Remember, the OEM Gasket is Teflon Coated, and that's what I used when I repaired my Ex the First Time.
Second, I installed the five bottom oil pan bolts, and torqued them down in two stages, 1st 3lb ft then 7lb ft.
All five bolts were dry (No oil & no threadlock).
Observation & Ultimate Question
* To date I haven't found a write-up on replacing the 4.0 OHV Timing Cover Gasket as extensive as what I originally wrote. Hence my wanting to get all this info out there as I feel that this is easily a 400,000 Mile motor (if properly maintained).
* Since having this Timing Cover oil leak, I've found online articles on other engines (i.e small block Ford 302 and Cummings Diesel) that have timing cover oil leaks, with timing cover construction similar to the Ford/Cologne 4.0 OHV (a Timing Cover with a Water Pump mounted on the front = high weight load, high heat cycles, and lots of vibration).
* With the ABOVE point in mind, I've read well-written articles talking about two significant differences with regards to how I made my original repair.
A) 1st = Torque the Oil Pan Bolts FIRST (pulling the Timing Cover DOWN), and then torque the Timing Cover 2nd.
This method/order of operation takes care of the "gravity factor" first,
and then connects the Timing Cover to the engine block.
B) Using Thread Lock - Loctite BLUE - on BOTH the Oil Pan Bolts and the Timing Cover Bolts to deal with the weight of the Water Pump hanging off of the timing cover, the heat cycles of the Water Pump, and the vibration of the Water Pump.
So - what say you?
7 years / 40,000 Miles ago, due to an Anti-Freeze Leak on the Driver's Side, I replaced the Timing Cover Gasket on my 4.0 OHV, and wrote an extensive write up on it.
LINK: Removing timing cover on 4.0 OHV
History: The entire time I've owned my Ex, it has never leaked oil. To clarify, it's weeped oil, but never leaked oil to the point where it left small puddles on the garage floor.
Specific Problem: Recently, my Ex has suffered a pretty major oil leak from the Timing Cover.It drips down from the Timing Cover, and leaves small puddles of oil on the garage floor.
In short, I think the OEM FORD Green Teflon Coated Timing Cover Gasket slipped down, and allowed oil to leak.
If you look carefully at the two pictures BELOW, the chopstick is pointing to where the the oil leak is starting from. Note that the Timing Cover Gasket is not exposed past the Timing Cover. In effect, it has "sucked below" below the timing cover between the 2nd and 3rd bolt from the top Timing Cover Bolt, on the Passenger Side.
The picture BELOW shows where the Timing Cover Gasket has "bowed" outwards, within the valley that is to release Anti Freeze when your timing Cover Gasket has reached the end of it's service life. It's my feeling that that the Timing Cover Gasket gasket is bowing outwards indicates that the Timing Chain Cover and Gasket are shifting down towards the ground.
Seven years ago when I replaced the Timing Cover Gasket, there was next to no info on the internet about this procedure on a 4.0 OHV. To this day, there is still next to nothing. So I fell back on my shade tree mechanic skills/experience; First I cleaned all of the gasket mating surfaces on the block and timing cover. Since the gasket is Teflon coated, there was very little to clean on BOTH the block and the Timing Cover.
Then, I cleaned out all of the timing cover bolt holes with spray parts cleaner, chased them with a tap, and then blew out the holes with compressed air. I followed this up with cleaning all of the bolt threads with a wire brush, cleaned the threads with parts cleaner, and then wiped them down with a high-nap cotton towel.
On the five oil pan holes/bolts that mate to the bottom of the Timing Cover, all that was required was to spray clean out the five oil pan bolt holes with parts cleaner, and stick a clean Q-Tip in each hole to clean/dry it out. The five oil pan bolts were cleaned with parts cleaner, and dried off with a high-nap cotton towel.
REASSEMBLY: The reassembly was as follows. First, I installed the timing cover and timing cover gasket. I torqued them in a "star" type order like you would a wheel, so as to evenly distribute the load - i.e. bottom left, top right, top left, bottom right. I torqued all bolts in three stages, first to seven pounds, then to eleven pounds, and finally at 15 lb ft. ALL bolts were dry = no oil & no threadlock/loctite. Also, The Block sealing surface and Timing Cover sealing surface were left DRY (NO OIL) This is how the Original Engine left the factory and lasted 13 years / 165,000 Miles before the gasket failed, and anti-freeze leaked from the Timing Cover Leak Channels. Remember, the OEM Gasket is Teflon Coated, and that's what I used when I repaired my Ex the First Time.
Second, I installed the five bottom oil pan bolts, and torqued them down in two stages, 1st 3lb ft then 7lb ft.
All five bolts were dry (No oil & no threadlock).
Observation & Ultimate Question
* To date I haven't found a write-up on replacing the 4.0 OHV Timing Cover Gasket as extensive as what I originally wrote. Hence my wanting to get all this info out there as I feel that this is easily a 400,000 Mile motor (if properly maintained).
* Since having this Timing Cover oil leak, I've found online articles on other engines (i.e small block Ford 302 and Cummings Diesel) that have timing cover oil leaks, with timing cover construction similar to the Ford/Cologne 4.0 OHV (a Timing Cover with a Water Pump mounted on the front = high weight load, high heat cycles, and lots of vibration).
* With the ABOVE point in mind, I've read well-written articles talking about two significant differences with regards to how I made my original repair.
A) 1st = Torque the Oil Pan Bolts FIRST (pulling the Timing Cover DOWN), and then torque the Timing Cover 2nd.
This method/order of operation takes care of the "gravity factor" first,
and then connects the Timing Cover to the engine block.
B) Using Thread Lock - Loctite BLUE - on BOTH the Oil Pan Bolts and the Timing Cover Bolts to deal with the weight of the Water Pump hanging off of the timing cover, the heat cycles of the Water Pump, and the vibration of the Water Pump.
So - what say you?
- Have you ever done this repair and experienced what I have experienced = gasket slipping DOWN?!
- What do you think about torquing down the Oil Pan 1st, and the Timing Cover 2nd?
- Have you used thread locker / Loctite Blue on the Timing Cover & Oil Pan Bolts with success?
- Any and all comments are welcome!
Seriously - Don't worry about re-using the TTY Harmonic Balancer Bolt. It's very large diameter and not going to break in your lifetime. I've re-used mine based on the many successful reports of others, and have taken it off & reused it twice now - no signs of stress/cracks/imminent failure. 
I'll give 'em to you tonite/this weekend as I read that you're not involve in the repair yet.
