Chapter Three /Gearbox Oil Change on the 308 GT4

Chapter Three /Gearbox Oil Change on the 308 GT4 Ferrari

(This procedure should also work with slight modifications to the 246, 308, Mondial & 328 series.)


My dream is to share what I have learned working on my 1975 308 GT4. I am working on a book "Ferrari Service for Dummies or What I Learned on the Internet" Here is my third installment. If you find any mistakes please let me know and I will revise it. As most of you may or may not know, I decided 11 years ago that I wanted to do my own work as I loved my car so much I couldn't trust anyone to touch my precious Ferrari. I started on the original Ferrarilist.com and met many members who guided me along the way, many are here now also. I also had help from several experienced Ferrari mechanics whose names will be withheld as not to embarrass them with my acquaintance! I am also on several other Ferrari lists, as I am a nut and have all this free time when I am not working 10 hours a day! I hope you enjoy what I have written and I can help some other poor soul who was as lost as I was 12 years ago. Please give me feedback, as I am in the slow process of becoming an amateur Ferrari mechanic! Respectfully, Rob (Robertone) Garven



Tools and or supplies needed:

1. 6 Quarts suitable oil (Swepco 201 80W-90W, Agip Rotra LSX SAE 75W-90W, Redline 75W-90W) Oil needs to have a friction additive for the clutches in the differential!
2. 10mm & 12mm allen hex wrench
3. 19mm & 22mm open end wrench
4. Suitable drain receptacle to catch and recycle oil
5. Rags or towels to wipe up spills etc.

Optional tools:

1. 1 funnel and a piece of hose approximately 10 inches long.
2. 1 creeper
3. 1 large piece of card board (To catch any oil that may splash.)
4. 1 box of latex gloves
5. 1 shop apron


Note: Never get under your car supported only by jacks. I have done this personally but I love my car more than myself. If you do this, make sure you have a good insurance policy. Your family will thank you, and at you memorial I will tell them I warned you in advance and try to buy parts off your car!



1. Make sure all work is done on a level and clean surface, you are sober and at least someone is around, (in shouting distance) in case you have an emergency. Get all the supplies you need ready at hand. (See figure 1 & 2)

2. Raise car to a suitable height (See chapter 1), or use a lift, make sure the car is stable and even. If you use jack stands make sure that they are placed so that they will not get in the way of your drain receptacle and are more importantly placed on the main tube frame in the appropriate locations.

3. Remove the battery ground cable. (See figure 3) I have a green spin off knob that disconnects the battery ground cable and is very handy, not only when working on the car but when leaving it for an extended period of time as not to drain your battery. Note: I have never had any battery drain even when the car has set for over a month, some models have more drain and even need a trickle charger to keep them charged for as little as two weeks!

4. Loosen the 22mm transfer case fill plug first, because if you drain the transfer case and can't get the fill plug off, well you get the idea! (See figure 4 & 5)

5. Place the receptacle under the transfer gear drain plug. (See figure 6)

6. Loosen the transfer gear drain plug with a 19mm wrench. (See figure 7)

7. Let the oil drain from the transfer case. There is not much oil in there but I place a receptacle and funnel under the hole to catch it all and leave it there for a while.

8. On the GT4 you must remove a rear aluminum heat shield cover that covers the gearbox overflow plug and hole. (See figure 8)

9. Remove the gearbox oil filler / overflow plug with a 12mm allen socket, you will need an extension to reach it. It is on the rear of the gearbox near the left side of the differential. (See figure 9 & 10)

10. Remove the gearbox drain plug with a 10mm allen socket wrench. This plug is located on the bottom of the car very near the engine oil plug. It is marked OLIO CAMBIO. I have heard several horror stories of someone draining the engine oil thinking it was the gearbox oil and well as stupid as it sounds, they were true stories with disastrous results. (See figure 11 & 12)


11. Be advised there is allot of oil in there so after you loosen the plug, I hold it up to the threads after it is completely unthreaded and with one quick motion, move it away from the hole allowing the 6+ quarts of oil to drain into your suitable receptacle. If you are using one similar to mine that are available and given out by may local cities to help manage oil wastes do not forget to remove the cap, drain plug and pop the relief cap. I unwittingly forgot to remove the drain plug in the receptacle only to have the oil start to overflow and reach into the hot gearbox oil to remove it what a mess. Learn from my dumb experiences. (See figure 13)

12. Let the oil drain for as long as you can. One hour is sufficient to drain almost all the oil.

13. I must mention here that I love the smell of gearbox oil. This has nothing to do with the procedure but what the hell I said it anyway!

14. Now your oil is probably all drained. I now clean the threads and magnets on the OLIO CAMBIO drain plug and replace it, along with the transfer case drain plug. It is recommended to use a new copper washer. I have heard aluminum is good also. I use a fiber one as it lets me tighten the plug with some fudge room. (See figure 14 & 15) With the metal washers any tighter than tight is stripped! I have also heard that if you anneal the old washer it works like a new washer. This entails holding it over the stove burner until it turns red hot then letting it air cool. I think this makes it softer, but remember I am not a scientist! If I were, I would be paying a real expert to do all this!!! Note: If you use the fiber washer I have had some that were slightly loose when I went to change to oil, so if you use one use it at your own risk. Ferrari recommends a NEW copper washer each time the plug is fitted! I am sticking to the fiber ones!

15. Now the fun part, adding the oil. I improvised an oblong funnel with a piece of hose attached to it to just fit into the transfer case fill hole and sit neatly above my ignition coils. (See figure 16,17 & 18) I am sure there are a thousand ways to do this but after 10 different tries this is my suggestion as the most efficient way. You can of course fill the gearbox from the side filler hole, but that is very stupid, needs more tools and is totally unnecessary. The transfer case has a small hole that leads to the main gearbox so filling it from the transfer case hole has two main advantages. 1. It fills the transfer case without having to resort to some kind of measuring cup etc. and 2. It is much easier. Anyway, I have bought 5 gallon buckets of the Agip gearbox oil and had a swell time shaking them to get the limited slip additive to mix correctly, only to have to hold the heavy pail at an awkward angle for a long time to pour the oil in getting down off my step stool to check every once and a while that the gearbox is full and that oil is flowing from the rear side overflow hole. I have recently found that Agip sells the same oil in 1 liter containers making it much less exciting but also much less a pain in the ass. (See figure 19). http://www.americanagip.com/ Several famous Ferrari Service technicians have recommended the Swepco 201 80W-90W gear lube. http://www.swepcousa.com/lubesite/products/h201.htm It is non-synthetic and has a limited slip additive in it also. I have heard so many good things about this gear oil that I drained out some fresh AGIP to fill the gearbox up with the Swepco. I will let you know how it works. One friend who uses it says he can shift into second when cold and that since it is a blue color it is easy to determine what fluid is leaking, if you have that problem! You know the old joke if your Ferrari doesn’t leak it is out of oil. Rolls Royce calls it “controlled seepage”! You continue to fill the transfer case fill hole until oil starts to run out of the rear vertical gearbox filler hole. (See figure 20) After cleaning the rear drain plug now is the time to replace it with your appropriate washer. Don’t get it to tight or you will strip the box (read here $$) or to loose and it will fall out. Go read Goldilocks and the Three Bears and you will find the right compromise. I always tighten it then give it one little extra umph. I use as short a ratchet, as I do not want to strip the threads.

16. It is now time to replace the transfer case filler plug. (See figure 21) I always add an extra pint or so gearbox oil in before it is all closed up in case of leaks etc. I have also heard that 5th gear is the highest and sometimes get starved for oil and since I want a little extra insurance I add a few drops more.

17. That’s about it. I usually spend about 4 hours (or 4 days depending on my mood) wiping everything off and cleaning everything accessible as that is the type of guy I am! Now you can check your clutch alignment hole (in early 308’s), bleed your brakes or change your coolant, since you are already there!!!



Legal disclaimer: I am not an expert just an experienced owner so the techniques and procedures I describe should be used with care and caution. Any damage incurred to vehicle, property or persons is the sole responsibility of the owner. Note: I have a sense of humor, you may not, please take this into account while reading this, as this is therapy for me!

Next chapter, Chapter Four / Coolant Change

 

Robert,
This is awesome stuff, but you gotta post these in the 308/328/Mondial section so that we can find it in the future!

Great work!

 

Awesome writeups!! It's so much better with lots of pictures. Thanks for the taking the time to snap away. I know it is kind of hard to reach for the camera at every step of the way with your dirty/greasy hands, but the Fchat community thanks you for your diligence.

 

Well, I didn't plan on changing my gear oil, but your instructions are so clear I think I will. Keep up the good work. I have a 80 308 GTSi.

Thanks

Marc

 

Coincidently I just did this yesterday.I used Redline oil.

 

Robert out of curiosity could you tell me what is that part that is in pictures 17 and 18 in front of the funnel that is round and gold cad plated which seems to be attached to the top of the transfer gear case.It appears to have a braided hose leaving it.I dont have this on my car.

 

That is the smog pump one way valve that lets air go from the pump but not back to the pump from the injectors, The gt4 has 2 pumps and two of these valves.
Miine are only working in one direction! ;-)

Rob

 

That is one clean engine!!!!

 

Thanks Robert.I dont have and there doesn't seem to be any evidence of my car ever having any of the smog pump parts

 

I am attempting to change the gear box oil today in my '85 308. I am attempting to get the 12mm Hex bolt out of the top of the transfer case, but it is seized in there. I have heated it with a torch and hit it with my impact wrench, but it will not budge. I was able to remove the small screw that is below it on the transfer case. Is this an option for filling the transfer case with the 3.8 ounces needed? It would be tough given how small the hole is, but getting the top bolt out does not appear to be an option. The top (larger circle in the picture) in the hex bolt, and the bottom (smaller circle) is what I am inquiring about. Your insight would be appreciated.
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Technically, yes, it would be OK if you can get the few ounces of fresh gear oil into that small hole (although the flow rate into the hole may be very, very slow) -- that small plug is not really meant to ever be removed and should be quasi-permanetly sealed with something like Loctite PST (or something stronger) on the threads. But I'd still work on getting the real fill plug out for the long-term -- are you also soaking overnight(s) with a penetrant oil (PB Blaster, Kroil, etc.)?

 

Thanks for the feedback. When I got that little srew out, I saw that someone had drilled it and used a screw extractor to get it out. I have a feeling that the hex bolt has been frozen in there for a while. To answer your question, I had put WD-40 on it last weekend and let it soak, but I am going to run to the hardware store and pick up some pentrating oil, hit it with that, let it soak for a week, and try it again next weekend. I agree, long term I need to get this corrected. I have a feeling one of the previous owners did not torque it down properly (or should I say the shop they used). Thanks again for your input.

 

Joe, if its that tight, i would advise you order a new plug now before you get the old one out. i bet its going to get damaged when you get it out. a new one with anti seize will make things much easier next time.

drain and filler plugs are cheap enough that its good to have a few if you mess with these old cars much.

wd40 is terrible at loosening parts in my experience. kroil and PB Blaster are far superior. i dont even buy wd40 anymore. BreakFree is a superior lube / water repellent, if you need something for that purpose.

best of luck.

 

Thanks. I actually went out and purchased some PB Blaster and soaked it down good. I am going to let it soak in until next weekend. Great minds think alike. I just ordered a new bolt and new washers for all the plugs. I am actually fearing the worse though. It is supposed to be a 22mm bolt, not a 12mm hex bolt. I am fearing that it might not have been the right part and someone forced it in.

Another Question: Anyone know if there is a gasket that goes under the transfer case cover (the cover shown in my picture) or do I just use some standard high temp gasket sealer. I am looking at the parts manual, and I am not seeing a gasket (in word file attached).

I think I may have to take the transfer case cover off in order to get the bolt out.
View attachment Transfer Case Cover.doc

 

That would be my suggestion, to remove the gear cover. The transfer cover has no gasket but care needs to be taken to remove it not to mar the surfaces. It also has some important alignment dowels which should be on the studs so take care not to lose them or replace them if left off, by the last tech. Also the middle gear just floats in there and there are some needle bearings also. Im not sure it is important but some have told me ( after I was finished) to mark the meshing of the gears if you remove one.I bought a small pen torch and it has been real helpful in getting a small amount of heat in a small area. I used 3 bond for the seal, a small wooden shims to pry it off. good time to check the gears retaining nuts etc.

The joke is always remove that nut first before you drain the GB!



I think the bolt type is the correct one for my car, but not sure about yours.

Good Luck.

Rob

BTW I am using Redline 75-90 NS and it is the best I have tried by far!!
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On my 328 that top fill bolt was super hard to remove, even though I was very careful to to not over torque it, and had only reinstalled a couple weeks prior, AND used anti-seize. Not sure what is up, but I would only tighten very lightly.

 

Loctite 518 (an anerobic sealant) would also be an acceptable sealer for that gasketless joint (you need very, very little sealer so don't over-apply. You only need enough to "fill-in" the surface roughness on each part -- i.e., the two parts are tightened into metal-to-metal asperity contact.)

 

Steve,

I learned a new word from you today. The closest word I knew to that one was ass-parity!

Rob

 

Along the lines of Mike's suggestion in the other thread (that applying some torque in the tightening direction to try to "break" things loose wouldn't be bad), it wouldnt hurt to rap the head a few times around the circumference with a hammer IMO -- i.e., soak overnight, hit a few times with the hammer, soak overnight, hit a few times, etc..

 

Gears have 27, 28 and 30 teeth if I counted correctly from your pic, so after 30 revolutions (is that correct) all teeth from a gear have met all teeth from the other.

 

Not quite. For the 27T gear meeting the 28T gear, since the difference is only 1 tooth, every tooth on one gear eventual meets every tooth on the other gear. However, for the 28T gear meeting the 30T gear, every tooth on each gear only meets every other tooth on the other gear. For example, start with tooth #1 on the 30T gear meeting tooth #1 on the 28T gear. On the next rev, tooth #1 on the 30T gear meets tooth #3 on the 28T gear, and then tooth #5, #7, #9, #11...#27 and then back to #1 on the 28T gear (i.e, tooth #1 on the 30T gear never touches the even-numbered teeth on the 28T gear). It's not a super-huge point, but it's best to not change it if you can remember to mark things. In the order of importance, I'd put:

1. Don't flip the middle gear over (I can't recall if this is possible or not, but, if so, don't do it).
2. Don't flip the needle thrust bearings over (i.e., don't reverse their direction).
3. Keep each needle thrust bearings on its correct side of the middle gear.
4. Keep the phase between the 30T gear and the 28T gear the same.

 

I am applying this philosophy. I won't be taking the car downoff the lift until saturday, but each night I am hitting the bolt with some PB Blaster then hitting it with some persuasion (hammer). I'll let the group know on Saturday if this thing will break loose.

 

Well, I never could budge that top 12mm plug loose. I soaked it with PB Blaster for a week. I hit it with some heat. I tapped it with a hammer. I tried tightening then loosening. Nothing could get that to budge. I ended up filling the differential through the fill plug and filled the trasfer case through the small alloy plug using a syringe type injector that I found at the hardware store. I have too many other projects for this "off season" to remove the trasfer case cover to get the plug out, but I have added that to 2009 winter project list. As a side note, on the transfer case drain plug, I had to put my impact wrench on it to get it off (900 ft/lbs for about 15 seconds to break it loose). Aparently the techs that worked on it before never heard of a torque wrench.

 

To update this I last switched to Redline 75-90 NS. I noticed an immediate difference in shifting ability especially at w2nd gear cold and would HIGHLY recommend this to any onw with a 308. Some have added a LS additive or added some redline with LS but I found I had NO problems whatsoever with chatter or anything just smooth shifting.....

 

Joe,

Did you ever get that transfer case fill plug off?

Rob