| Author | Message | ||
| Steve Magnusson (91tr)
Member Username: 91tr Post Number: 567 Registered: 1-2001 |
Thanks Eric (and Bill for your suggestion -- I'll try it). Here's the sketch of the special "flattened ball end" puller that can be used to (destructively) withdraw the inner and outer raceway of a ball bearing simultaneously as descibed in my earlier posts below:  | ||
| Eric Eiland (Eric308gtsiqv)
Junior Member Username: Eric308gtsiqv Post Number: 181 Registered: 11-2001 |
Steve: finally converted the file for you -- it's on the way via e-mail. Hope it works  . | ||
| Bill Sebestyen (Bill308)
Junior Member Username: Bill308 Post Number: 112 Registered: 5-2001 |
Steve, A simple way to convert a *.pdf file to a *.jpg file is to perform a print screen, then a "past special" into another application like Powerpoint. From Powerpoint you can save the slide as a *.pdf file. | ||
| Eric Eiland (Eric308gtsiqv)
Junior Member Username: Eric308gtsiqv Post Number: 180 Registered: 11-2001 |
Steve: just checked my e-mail, and the .pdf file came over fine. I'll convert it first thing in the A.M. (at the office). | ||
| Eric Eiland (Eric308gtsiqv)
Junior Member Username: Eric308gtsiqv Post Number: 177 Registered: 11-2001 |
Steve...I'd be glad to convert the .pdf to .jpg for you if you'd like. | ||
| Steve Magnusson (91tr)
Member Username: 91tr Post Number: 565 Registered: 1-2001 |
Rob -- no photo of the tool available, but I'll email you a sketch of the special non-head end of one of the special bolts (it's a .pdf file -- anyone know how to convert .pdf to .jpg so I could post it?). This sketch is based on the outer cam bearings from my ex-'78 (with the later design arrangement) which had a 40mm OD x 17mm ID x 12mm width sealed ball bearing with a complement of (8) 6.75 mm diameter balls -- but the concept could be resized for any ball bearing (except a full complement type). | ||
| Robert W. Garven Jr. (Robertgarven)
New member Username: Robertgarven Post Number: 11 Registered: 2-2002 |
Thanks Steve, Do you have a photo of his tool? Supposedly baum tools has them but they wanted to know what size I needed. I have been told it is called a blind bearing puller. Does anyone know what baum tool part the right one would be I imagine that they are pretty expensive and do not want to get the wrong size. Rob | ||
| Steve Magnusson (91tr)
Member Username: 91tr Post Number: 564 Registered: 1-2001 |
Timothy -- I borrowed such a "puller" from Tony P. (Modena Motors) and replaced the outer cam drive bearings on my ex-308 circa 1992. | ||
| Timothy J. Dressel (Tjd)
New member Username: Tjd Post Number: 44 Registered: 4-2001 |
Steve, Does the puller you described actually work well? Have you used it successfully? --tim d | ||
| Steve Magnusson (91tr)
Member Username: 91tr Post Number: 562 Registered: 1-2001 |
Rob -- One method to get the outer bearing out of the housing is to use a "special" puller -- which uses 2 threaded bolts with flattened ball shapes on the non-head end (the same diameter as the balls in the bearing). You break the cage out (which allows you to slide the balls out of the way) and the flats on the "ball" bolt ends allow them to be placed between the two races and then turned 90 deg to engage both races (of course the two threaded bolts are positioned ~180 deg apart). A simple two-legged puller is then used under the bolt heads (and pushing on the shaft) to withdraw the bearing out the front of the housing. I'll send a sketch to better explain. | ||
| Robert W. Garven Jr. (Robertgarven)
New member Username: Robertgarven Post Number: 7 Registered: 2-2002 |
Thanks for all the help guys but I am stuck. I have the earlier gt4 engine which has the pulley then the cam seal then a snap ring, bearing, spacer, snap ring then gear. the pulley came off easy enough, then I removed the outer snap ring. I sat ther for several hours trying to figure out how to remove the parts and cannot figure out a way. since there is a snap ring behind the bearing, obviously the shaft has to be pressed out the back somehow? If anyone has done this and can provide a sequential directions I would be grateful. | ||
| '75 308 GT4 (Peter)
Intermediate Member Username: Peter Post Number: 1614 Registered: 12-2000 |
When re-installing the bearings on the shafts, I just used an assortment of either steel pipe, or a deep socket, which ever fit the best and pressed them on in an ordinary bench-vise. If you're pressing the bearings on the shaft, press on the inner race. Pulling them off, I assume you have some sort of gear puller? These will work fine. Again, try to grab the inner race to pull off. If I remember correctly, I don't think you can get right behind there when its on the drive gear, so you may have to pull from the outer race. Once you get clearance, pull from the inner race. If you didn't experience any oil pressure losses before the rebuild, you shouldn't have to go into the oil pump. The pressure relief is a spring-loaded piston, it dumps all excess oil pressure into the pick-up passageway (that I don't understand. To me, this looks like it would pressurize the incoming oil. Believe me, this is where it dumps into). | ||
| Jeff 77 GTB (Jbk)
Junior Member Username: Jbk Post Number: 54 Registered: 4-2001 |
I just bought a set of Nick's lightweight tensioner bearings and they look really great. They appear very well made and I'll put them in once I get the cam seals changed and replace the belt. Only $20 more than originals and the bearing is replaceable by itself for next time. | ||
| Edward Gault (Irfgt)
Member Username: Irfgt Post Number: 852 Registered: 2-2001 |
I personally do not like the factory timing belt idler bearings. Nick sells an aluminum replacement bearing that is lighter and has a replaceable bearing that has less friction than the original. If I was going to stick with the original belt system I would at least upgrade the bearing. | ||
| Robert W. Garven Jr. (Robertgarven)
New member Username: Robertgarven Post Number: 6 Registered: 2-2002 |
Dear new and old friends :-) I finally got the front timing cover off only after having to remove the waterpump and housing as on my car(engine #1306?) there was one timing cover nut that you could not get off without removing them. I then used some wood wedges to pry the front cover off. One of the block bearings came off on the shaft. I pulled it off and it did not fit into the hole it came out of so I think that is ok. One outside bearing is so shot you can move it at least half an inch and the other is also failing so i think I was lucky not to have had a failure. I am still needing advice on how to install and or remove the bearings. I do not want to put undo pressure on the races. My other question is should I dissasemble the oil pump. I would like to but I have no experience and do not want to do anything to mess it up. I know it has some pressure relief valve on there can some one explain how it works. I also would like your opinion on my belt tensioner bearings, I changed them 1.5 years ago and think that they should be fine Thanks for all the suggestions, Ric and Steve have helped me do most of my other work and I appreciate any advice given. Rob 308gt4 #10766 | ||
| Edward Gault (Irfgt)
Member Username: Irfgt Post Number: 851 Registered: 2-2001 |
It won't allow me to post them saying they are too large and I do not know how to reduce them. The old site used to let you post anything. | ||
| Edward Gault (Irfgt)
Member Username: Irfgt Post Number: 850 Registered: 2-2001 |
The bearings that I removed from my engine were the same fit as the ones that I replaced them with and had to use very little pressure to install them. I used Federal bearings to replace the originals. I made the new timing pulleys so that they are not a press fit and you can install them with hand pressure without risking damage to the flanges if they ever have to be removed. I am going to try to scan and post the pages from the Ferrari parts book that I refered to if they will fit in the new format that we have now. Here goes.  | ||
| Timothy J. Dressel (Tjd)
New member Username: Tjd Post Number: 43 Registered: 4-2001 |
Regarding Edward�s comments of the prevalence of the bearings, I suggest some caution. Although the bearings in the timing cover are of the same size and same general part number as the generic bearing readily available, their clearance specification is not as common. Get out your magnifying glass. On the common bearings you can find �/c3� . On the Ferrari supplied bearings you should find �/c4� , indicating greater clearance. This is to allow high speeds as well as to compensate for the overly tight fit (in my opinion) on the shaft. I�m working on applying a /c3 version of the bearing, but I�ll be honing the i.d. to lessen the tight press fit. Also, the bearings I�m using have a fiber cage rather than the metal cage. The failure of the metal cage that the SKF guys described to me that they found in the racing Ferraris was the same as I encountered in my 308gt4 at 90k. They suggested removing the tight fit. Since I haven�t proven this approach, I�ve been reluctant to mention this in FC or advise anyone else trying it. Edward, your comments on this are welcome. Also, Edward, what would you say about slightly (approx .001�) decreasing from factory spec. the i.d. of the drive sprockets that you manufacture and then having the shafts ground to the slightly decreased diameter? That is, so the bearing wouldn�t have to be tightly pressed. --tim d | ||
| Edward Gault (Irfgt)
Member Username: Irfgt Post Number: 849 Registered: 2-2001 |
I thought the same thing, however I have quoted directly from the Ferrari parts book and from the actual experience I have encountered. | ||
| Steve Magnusson (91tr)
Member Username: 91tr Post Number: 552 Registered: 1-2001 |
Edward -- good post, but the change was introduced somewhat earlier -- my ex '78 308 had engine #00455, and it had the later design with the lip seal between the bearings (although back before the 17 digit VINs the model years are admittedly more vague). | ||
| Edward Gault (Irfgt)
Member Username: Irfgt Post Number: 846 Registered: 2-2001 |
There is at least two designs of the cam drive setup. The first design is before engine #00133 and uses an external seal that presses into the timing cover case from the outside and uses a drive pulley that has a machined lip that the seal rides on. From engine #00134 they use an internal seal that presses in from the inside of the timing cover. The later design uses a #201 bearing in the block and a # 6203 bearing in the timing cover. The block bearings are the same part number for both designs, but the Ferrari book shows a different case bearing part number. This could be only a difference in whether the bearings are sealed or not. If you get a sealed bearing and need an unsealed one, the seal will pop out with a small screwdriver. This engine number design split came sometime in the 1979 model year. We ran into this problem when I was developing my timing pulley system. The late pulleys and early pullys will not interchange and I had to make a "one off" run of the early pulley for a customer. These bearings are a common part and are available at any parts store. They can also measure your old bearing and cross reference the measurements to a number. | ||
| BretM (Bretm)
Intermediate Member Username: Bretm Post Number: 1754 Registered: 2-2001 |
Apparently they go bad fairly often, or at least when doing engine work should be checked and probably replaced. I checked mine briefly, but haven't really gotten into them. The seem to have little play in them as far as I can tell without taking off the pulley. | ||
| Richelson (Richelson)
Member Username: Richelson Post Number: 455 Registered: 12-2001 |
I didn't know that these went bad. I haven't heard or seen many records of them being replaced on 308s. | ||
| Brian stewart (Eurocardoc)
Junior Member Username: Eurocardoc Post Number: 173 Registered: 11-2001 |
The bearings are a ball style, bring the temperature around the outer race up with a torch after removing the circlips and it falls out easily. Any bearing supplier can sell you the bearing if you want a sealed one or two sides they can cross reference. | ||
| Robert W. Garven Jr. (Robertgarven)
New member Username: Robertgarven Post Number: 5 Registered: 2-2002 |
I have about 40 hours into this so far. The bottom studs holding the front cover came off easy it was the oil pick-up tube nut ( see Rics photo) http://www.rainbolt.com/ferrari/qvs/ that was hard to remove but after calling Ric he suggested a socket with the swivel attached and I went to Sears got one and the nut came off in five minutes after I had spent about 5 hours trying to remove it. I did a major service 1.5 years ago and this is about the only thing I did not replace or refurbish. My engine was making a steady intermitant growling, which I knew was serious. I am changing both inner and outer. I have the unsealed bearing but I do think they get a bit of oil. I have been told that usually after new belts are tightened they sometimes go bad , which is probably my case. Hopefully Ric will post the proceedure as once I have the front cover off I am at a loss on how to remove and replace the bearings properly without placing the wrong stress on the races. Rob | ||
| '75 308 GT4 (Peter)
Intermediate Member Username: Peter Post Number: 1609 Registered: 12-2000 |
On older 308's like mine Paul, the outer bearings are open. Do you happen to know the manufacturer's part # for your QV sealed bearing? (No, not the Ferrari number, but there should be an SKF, or NSK, or...., number printed on the side of the bearing race). | ||
| magoo (Magoo)
Intermediate Member Username: Magoo Post Number: 2033 Registered: 2-2001 |
The outer bearing goes first in most cases. | ||
| Paul Sloan (Sloan83qv)
Junior Member Username: Sloan83qv Post Number: 229 Registered: 3-2001 |
On the 308 QV's the inner bearing is oil bathed but the outers are sealed bearings that need no oil passage way. I would think it's the same on all 308's but maybe not. | ||
| Paul Sloan (Sloan83qv)
Junior Member Username: Sloan83qv Post Number: 228 Registered: 3-2001 |
From personal experience not replacing inner cam drive bearings when doing outers will result in another bearing failure a short time later. This is espically true if you had an outer bearing failure, outer bearing failure would put a load on inner bearing. Be smart pull the engine and do the job right the first time. | ||
| magoo (Magoo)
Intermediate Member Username: Magoo Post Number: 2030 Registered: 2-2001 |
Makes you wonder when you hear these love stories. This is probably what happened to Mitchel. Again one would think that the bearings would have a better oil supply than that. I guess if a frog had wings he wouldn't bump his ass when he jumps. | ||
| '75 308 GT4 (Peter)
Intermediate Member Username: Peter Post Number: 1607 Registered: 12-2000 |
The reason why they go, is they have a total lack of oil supply. The bearings supporting the inboard side of the cam drive gear are buried in the block and have a dedicated oil passageway, the front cover doesn't, and that's where these bearings are. They just grind-up. | ||
| Timothy J. Dressel (Tjd)
New member Username: Tjd Post Number: 40 Registered: 4-2001 |
Richelson, Before my cam drive bearing went out on my '75 gt4, I think I had heard it rumbling; but I didn't identify the problem. I noticed smoke from oil on the exhaust. The oil was from the seal, which quickly got very bad --lots of oil. The mileage was about 90k. --tim d | ||
| Paul Newman (Newman)
Junior Member Username: Newman Post Number: 90 Registered: 12-2001 |
Peter, to replace the cam seals, pull the cams. Another possibility is the cam drive seals that we are talking about right now. | ||
| Peter Delaney (Delaney)
New member Username: Delaney Post Number: 1 Registered: 2-2002 |
Hi! I'm new on the block! Have an '83 308 GTSi QV Scuro Blue (Euro). How difficult to replace the cam seals? How long should it take? I've a good set of tools and am fairly competent ... I actually use a torque wrench! I've got an annoying 2 - 3 drops of oil hanging on the oil pan every time I go for a drive. I pulled the pan because i thought it may be the gasket .. also had two stripped studs. No improvement. Could it be anything else? You've probably heard this before .. but this is one of the most informative sites I've found. Excellent! Appreciate any and all info! Pete | ||
| Brian stewart (Eurocardoc)
Junior Member Username: Eurocardoc Post Number: 170 Registered: 11-2001 |
Normally a loud growling noise, it may come and go. I have seen several needing replacement. The book time is 3.9 hours with engine out to replace seals and bearings! | ||
| Richelson (Richelson)
Member Username: Richelson Post Number: 454 Registered: 12-2001 |
Why did the bearings need to be replaced? How often do they go bad? What are the symptoms of the bearings going failure? | ||
| Richelson (Richelson)
Member Username: Richelson Post Number: 453 Registered: 12-2001 |
Is that picture out of the QV workshop manual? That is a nice daigram. | ||
| Ric Rainbolt (Ricrain)
New member Username: Ricrain Post Number: 9 Registered: 2-2002 |
See... http://www.rainbolt.com/ferrari/qvs/Diagram1.jpg We're talking about the bearings right behind the two drive pulleys. | ||
| Richelson (Richelson)
Member Username: Richelson Post Number: 450 Registered: 12-2001 |
What is a cam drive bearing? How often do they need replacing? I have never heard of them before so, any info would be great. | ||
| Ric Rainbolt (Ricrain)
New member Username: Ricrain Post Number: 7 Registered: 2-2002 |
I have done this "in-car" without splitting the engine and trans (more than once). It *IS* possible. It **IS** a major PITA! Given equal time, I would pull the engine to do it. But for those without an engine hoist, it is a viable alternative. It is also cheaper, in that you don't have to buy a new rear main gasket. The link Robert supplied is to pictures from a QV that we did this way. | ||
| Paul Newman (Newman)
Junior Member Username: Newman Post Number: 86 Registered: 12-2001 |
Brians right, yank the engine and split the trans and block to remove the front cover. | ||
| Brian stewart (Eurocardoc)
Junior Member Username: Eurocardoc Post Number: 168 Registered: 11-2001 |
Robert, the front housing has studs down through the transmission/upper crankcase housing so is almost impossible to pull in car. There are pullers which will fit the bearing allowing replacement in situ, they are size specific and expensive, available through Baum Tools. | ||
| Robert W. Garven Jr. (Robertgarven)
New member Username: Robertgarven Post Number: 3 Registered: 2-2002 |
Fellow Ferraristi, Thanks for your friendly repiles to my introduction thread. I am replacing the cam drive bearings in my 1975 308 gt4 as the rear outer one failed. I am doing this in car for several reasons, space and limited exprience being two. I have the oil pan, oil pick-up tube, crank dampner, alternator etc. off and will start to try to reomve the front housing. I am wondering how hard it will be to remove this. If anyone has any suggestions on how to accomplish this or how to replace or press in any of the front, rear bearings or seals they will be greatly appreciated. Here is a post from Ric of a motor he worked on http://www.rainbolt.com/ferrari/qvs/ if anyone has any ideas please let me know. Rob |