71OldsCut

Hi guys,

I think I am finally ready to start knocking things off the to-do list which is:

new exhaust from headers to tail pipes
new intake manifold to fix vacuum... hopefully
new HEI upgrade
remove/rebuild transmission

But, one thing I am thinking I should do is change the oil pan gasket. It leaks and there likely wont be a better time to do it. If the exhaust and trans are off, I should be able to lift the engine high enough to get the pan out right? If I had room and an engine crane taking the engine right out would be nice but I dont think I can quite do that.

I recall someone on hear saying they used a floor jack with a piece of wood to not damage the pan to lift the engine up a decent amount then put blocks between it and the frame to keep it up. Then took the pan off, cleaned everything up, applied the gasket and put it back on.

If I did it this way, is there any concern about having the weight of the engine push down on the pan when lowering the engine back into place or once it is snugged up it will be fine? I cant see it hurting the gasket but maybe it could?

I suppose this would also be a good time to replace motor mounts too. Amazing how one thing leads to another and another, and .....

Anyway, as always thanks for the help and tips.

Destructor

If you are removing the pan and you haven't already replaced the timing chain, do the chain also. By removing the pan already you have eliminated a major chore of timing chain replacement.

71OldsCut

Good call, as stated above, one thing leads to another and another... and now another, lol. But like the oil pan, I will hate myself if it needs replacing in a year or two knowing that I was a large part into the process and didn't do it. I will look into what is required to do this and add that to the list too.

Vintage Chief

I'm going to drop my pan, shortly. I have the intake manifold/valve covers removed. I just finished refurbishing them. I had a small leak from the intake manifold (perhaps in several locations but certainly at the rear gasket). I have a small amount of seepage from the rear main seal, as well - so, I'll update the rear main seal. While you have oil pan removed, examine your oil pump and your oil take-up screen. At a minimum you'll probably want to change the take-up screen. Additionally, I've tried several times to tighten my steering gear with no success; so, I'm going to change out my steering gear, also; since, I have now lots of working room & a good opportunity.

Do you have a paper copy of the 1971 OLDSMOBILE CHASSIS SERVICE MANUAL (CSM)? If not, get one.
Cheers.

71OldsCut

Hi, I have a Chiltons repair manual that I found on sale from someone locally.

Is the rear main seal something that is easy to change once the pan is off and transmission is out of the way? Perhaps this should be yet another thing added to my to-do list.

I will change the screen on the oil pump - might as well. Is there any value in just changing the pump itself, assuming this is something that can be simply done while down there? Or are these generally not an issue?

For the timing chain and gears - I guess to do this all the belt driven components and the radiator come out, and it can all just be accessed this way? Any tricks, special tools or difficult parts to doing this? I assume the new gears just go on the same position as the old ones and then just reverse the disassembly process? At this point I am really wishing I had the space and equipment to just take the engine out, lol. Oh well, it shouldn't be too bad with the car nice and high and a good creeper.

Well, that was a lot of questions, thanks for the help!

Vintage Chief

I've used Chilton's, Haynes, etc. before - they're 'fair', better on some cars, poorer on others. IMO, the best service manual for the 1971 Oldsmobile series is the Oldsmobile CSM - hands down. I did a quick search for you, this is about the least expensive original you'll find including the Fisher Body:
https://www.ebay.ca/itm/1971-OLDSMOB...7:pf:0&vxp=mtr

Vintage Chief

Rear main is easy. Easier when you have the manual. More space when the trans is off; yet, trans removal is not necessary.

Vintage Chief

There's always value in changing the oil pump (and take-up screen) - perhaps not so if the car has 10K miles on it. If you're changing the oil pump you're definitely changing the take-up tube & screen. The most difficult part is the oil pan removal; and, if you've pulled the oil pan, it's almost concomitant you should be changing (at a minimum) the take-up tube (and screen). Changing the oil pump is a great idea if you have no idea when the last time it was changed. There are very good YouTube videos on changing oil pumps and take-up tubes.

71OldsCut

Nice, while I am breaking the bank on all this other stuff might as well pick up one of these too, lol.

I was looking through my Chiltons manual and it actually has some pretty decent instructions and pictures for most of this work. As I am looking through that, the thought of a cam shaft cam to mind. I like the choppy idle and was thinking of doing this at some point, but if the engine is lifted slightly and the front is disassembled down to the timing chain and gears being removed, I guess taking the cam shaft out at this point isn't a big deal right? Is there a mild cam shaft upgrade that will get the choppy idle that doesn't really need new cylinder heads or are these generally a package deal?

I think the bigger question is - is this a smart move with all the other work going on? I have heard that cam shaft mods can reduce vacuum pressure. Considering that is the reason I am changing the intake manifold gasket, would changing the cam shaft erase any vacuum gains that the new gasket got me leaving me wondering if I have actually fixed anything? I suspect it should be fairly obvious with the way it runs once tuned and adjusted, but I am not sure.

The first start up is already going to be nerve racking enough with the new sound, having to get the tuning right, fuel mixture right, and of course frantically checking all over to make sure there are no oil, coolant or fuel leaks,lol.

Vintage Chief

IMO, you need to decide what you want this vehicle to be. I have briefly reviewed several of your other posts e.g. distributor, TDC, timing, shifting, etc. As an example, had you begun with putting a vacuum gauge to your hoses and measuring the vacuum (with a visual reference such as the CSM), you might have arrived at an early resolution to vacuum. Another example, such as your shifting - you believed it wasn't shifting into the3rd, yet the service tech had it on a hoist and it shifted both up & down into 3rd & 2nd. I can't think of any reason it wouldn't shift when it's on the ground - save for the torque converter. I'm not a transmission expert by any stretch of the imagination; yet, I didn't see anyone mention the torque converter. The torque converter is full of fluid and is under pressure - it's the liquid 'gateway' between the engine & the transmission (allowing each to spin somewhat independently). I could 'suppose' if you have a bad torque converter you might have an issue in shifting 'under load'. Again, I'm not a trans expert by any means. In trying to diagnose your shifting issue, I noted you didn't go WOT (you had hesitations) several times. Me, I'd punch that sucker WOT to see what broke.

POINT: If your vehicle is going to be a day driver pleasure cruiser, be mindful how much 'work' you're going to expend in it. Lots of folks are 'heavy' into rebuilds, street demons and the like. My point has nothing to take away from them - everyone picks their poison. Do you have to rebuild your engine, do you want to rebuild your engine, etc.? Your call - save some time to enjoy it. I hope my post doesn't come across any other way than to help you gain an understanding on what 'needs' to be worked on and what you 'want' to work on. Cheers!

71OldsCut

Good points, and don't worry, the point has been received as intended.

The car's purpose is a nice weather daily driver meant to enjoy and have some fun with. It just had some mechanical issues that needed to be fixed. I won't be the primary driver of the car so I just want to get a bunch of the issues fixed as well as some routine maintenance that has likely been over looked for many years done to make it as reliable and easy to drive for a long time to come.

The transmission, while it would get into third on the list, it didn't feel like a strong shift and seemed to hesitate. I doubt there has been much work done to the transmission over the years so I think a rebuilt is probably the right way to go.

The cam shaft is for sure not a required item, but I just figured if I had the engine stripped down to the point where changing it was right there in front of me, if there is a mild upgrade that didn't require new lifters or cylinder heads now might be the time to do it. Sort of like having the oil pan off lead to a new timing set and rear main seal. But, unlike those items this is not at all required, just a "while i'm this far" sort of thing, lol.

I am honestly a big fan of the resto-mod cars in the 300-400HP range that have the upgraded suspension and brakes, etc, but things like that are a bit out of the current price range. So, I just want to make this one drive as good as it can, sound as good as it can, and be reliable enough to drive regularly without starting issues, overheating issues or anything like that.

Hopefully that is achievable. I would honestly be thinking I should just have the engine rebuilt, but the shop I had it at was overall impressed and said other than the vacuum leak and worn out distributor the engine itself is actually in very good condition. I don't really have the money for a rebuild anyway I don't think.

Anyway, thanks again for all the help and tips. It is a lot to chew on so I will get the car up in the air this weekend and think it all over. Maybe make a must do and optional list and go from there.

Vintage Chief

I admire your efforts in addressing the issues.

71OldsCut

Well, it has to get done and with our long winters the car isn't going anywhere any time soon, lol. The car has already been sitting a couple of months and probably has another 4 months to go. That is a lot of weekends to pick away at things and start knocking things off the to-do list.

One thing I was worried about was getting the exhaust manifolds off without breaking any of the bolts off. I picked up some of that Kriol stuff, drilled 1/8" holes in the manifolds above the bolts so the fluid could get to the threads and let them soak for a few weeks, re-spraying them a couple time per week. Every single one came out nice and easy. The hardest part was getting some of the tabs out of the way that were folded over the bolts. Getting the rest of the exhaust system off shouldn't be too bad, and I will just keep going from there.

Cutlass Fan

An rv style cam would probably be the best choice. Any "lumpy" cam will reduce vacuum as well as low end power. Cutlass ef is the olds camshaft guru. If you change the cam you WILL need to change lifters.

olds 307 and 403

The big problem is the factory 24cc pistons, it gives around 8 to 1 compression, less if the head gaskets are changed. Cutlassefi does do custom tight LSA cams that are larger than stock.

tv442

71OldsCut

That actually looks like it could be a great solution for me. I am looking at it on an old screen that is fairly dark. So basically you made the wooden structure to jack up and support the engine from the front, but what is the back resting on - is the transmission still on and just resting at the trans mount?

Vintage Chief

Nice work - good engine-uity!
SUGGESTION: Remove the oil-fill tube - unless you enjoy a good fight. LOL It comes off VERY easily - takes at the most five minutes. Use a rubber mallet. Whack it anywhere you like - top, sides, bottom, top, sides, bottom, left>right, right>left, front>back, back>front. It is ONLY held in by compression from the top - no gaskets, no rings, no 'nuttin'. If you don't have a rubber mallet (best tool), use a hammer and place a small piece stock of wood (2"x4" or similar), thick piece of plastic/rubber, whatever and whack it. Simple to remove.

Vintage Chief

BTW, that washer fluid bottle is held in w/ x3 small screws on the underside of the fender well - provides a tad more 'elbow room'. You're look'n good.

tv442

BackInTheGame

Man I sure like that frame that TV442 built and used! I sure could have used that last year when doing my oil pan gasket. I could have gotten INCHES more clearance.

The way I did it, will likely need a new one anyway! LOL! Oh well, I'll do the rear main seal next time, too

Destructor

Nice support system, how was the condition of your timing chain? I have to do mine sometime. It's at 82,000 miles.

Vintage Chief

Very well built, solid, storage w/ minimal imprint (leg extensions come off, boom folds down) & a good price for ownership....since, you apparently don't know when you're going to stop.
https://www.oreillyauto.com/detail/b.../34786/2494215

tv442

tv442

71OldsCut

I will for sure have to rig something like this up. My transmission should be off at that point so I was thinking of trying to do something similar for the back of the engine using the bolt holes for the trans. I will just have to figure out a way to do that and leave enough room to get the pan off.
As suggested above, I have added the rear main seal to my list, but I was doing some research on how to change this. I actually came across a post on this forum and it seemed like the general opinion at least at that time was if it ain't broke, don't fix it - due to these apparently being difficult to change and in this guys case, the upper piece wasn't coming out.

How have you guys found these to be when changing them - do they typically come out without much trouble? Is installation typically straight forward too or should I be expecting a fight?

olds 307 and 403

They can be a real bitch to get the old seal out. A real stiff, yet still bendable wire is needed. The 292 Ford seal goes in very easy, I actually damaged one half of AMC 6 seal installing it, it is definitely a tighter fit.

71OldsCut

That is good to know, well not really but better to find out now than halfway through the job realising I have created a problem where there wasn't one before, lol.

I think I may revise my list back to just the exhaust, intake manifold gasket, HEI upgrade and trans rebuild. The car shows 53,000 miles and from what I understand timing sets should be done in the 80,000-100,000 range? So either I am under that range or if the odometer has been rolled over it likely was done once already. Or it has never been done, the odometer has rolled over and is way overdue... I will dig back through the old records and see if I can find anything on this. As for the rear main seal, I don't think it is currently leaking and should be fine until next winter.

I think it may just be easier to plan to take the engine out next winter and change the oil pan gasket, oil pump, timing set and rear main seal at that time. Should be a lot easier with the engine out. I was also thinking about a new cam shaft and cylinder heads so maybe all of that will be next winters list. Right now I would just like to get third gear, fix the vacuum leak and get it running properly. It would be a little rework doing the manifold gasket now and then having to redo it next year if I decide to try out some different heads, but I think that 'con' is out weighed by the 'pros' of getting the other items taken care of with the engine out.

Thanks to all for the tips, advice and suggestions. I can't wait for spring but I have not even gotten to the worst of winter yet....

71OldsCut

Hi guys,

Can I get your opinions on torque converters? Do they typically work problem free or can the internals eventually wear and go bad? I was wondering if I should buy new one while the transmission is out or is it generally OK to just re-use the old one? Also, does anyone know what the stock stall is? And last, it appears they are a one fits all across the GM cars for the TH350, is that right? There doesn't seem to be a difference from Chevy to Olds to Buick ect...

Thanks!

olds 307 and 403

The stock stall flashes around 1600 rpm, horrible in my books. Yes they technically fit in the trans, the TH400 as well. The issue is chebby's use bolt and nut converter attachment, which can hit the balance weights. Olds use bolt and lug attachment. Some of the aftermarket converters use the Olds style including this one, which has good reviews. The picture is generic.
https://www.google.com/url?sa=t&sour...4KVBd1QM2yqcPN

71OldsCut

Thanks for the link. That is much better both in price and reviews than what I was looking at. Forgive my lack of understanding with torque converters, I think I understand the basics of what they do, just get lost with the stall speed. Even with a stock setup, you still don't like the 1600RPM stall? Would going higher cause any drive-ability issues?

Looking at the guideline chart provided it looks like this one with stock specs would still be around 1600-1800 which is what I was looking for, but perhaps that isn't the best choice if it is being replaced.

olds 307 and 403

I find the 1600 rpm horrible with 9 to 1, 214/214 cam and 2.78 gears. It will barely spin the tires, I had a 2300 stall with 2004R trans, it would lay rubber for a 1/4 block. I have used a 1900 flash stall behind low compression 350's and 403's, it worked quite well. With headers and dual exhaust will give a noticeable performance gain.