Transmission and Engine mating

sojahseh · 08-23-2013, 06:30 AM

I'm at the point where I'm ready to put the drivetrain back in my 85 Carrera. I have the transmission and engine sitting on separate pallets. I have already installed the exhaust system on the motor, but from the look of it, it would appear that the crossover pipe will get in the way of the clutch arm if I try and mate the transmission to the engine.

Is this an optical illusion? Does the exhaust have to be off the motor to install the transmission?

Thanks in advance...

Matt

dalboa · 08-23-2013, 12:41 PM

Hey Matt,

When you say clutch arm are you referring to the clutch throw out shaft that comes straight down bottom of trans?
I recently dropped my engine & trans (85 Carrera) and pulled the trans off without any problems with the exhaust being in the way so I would say it shouldn't be a problem so long as you do not install the helper spring till after mating the two together. Let me know though as I'm currently a couple weeks behind you in my project waiting on clutch parts etc.

sojahseh · 01:51 PM

I ended up taking the exhaust crossover pipe out to ease install of the transmission. Like everything else I've accomplished on this project, I've had to redo and undo my work several times. Great learning experience. I have now separated and mated the transmission and engine at least 4 times now. What helps is after you have the fork seated in the TO bearing, if you have someone pulling the clutch arm toward the front of the transmission while you gently giggle the transmission back onto the block. The snag I've hit several times is the clutch forks not moving on and off the TO bearing readily.

Good luck. Hope that helps.

sojahseh · 08-23-2013, 02:19 PM

Take that back actually.

While removing the crossover pipe makes it easy, there is no way to reinstall the crossover after the transmission is back in place.

I think you need to remove the heat exchanger on the drivers side to get it in there.

-Matt

boyt911sc · boyt911sc's Garage

Quote:

Originally Posted by sojahseh

Take that back actually.

While removing the crossover pipe makes it easy, there is no way to reinstall the crossover after the transmission is back in place.

I think you need to remove the heat exchanger on the drivers side to get it in there.

-Matt

Matt,

You are doing something different (wrong) if you could not install 915 transmission with the engine (with complete exhaust system). Let's go back when you dropped the engine/trans together. How did you remove the transmission from the engine? Did you have the exhaust (HE) and cross-over pipe on the engine prior to separating the transmission?

During a typical engine rebuild, everything is installed back to the engine except the muffler. Then the transmission is hook up with the engine (SOP) with the starter. Look closely what's preventing you from doing this routine procedure. Pay attention to the three (3) transmission studs with respect to the axis of the holes. Line them up on the same plane or axis to mate it.

Keep us posted.

Tony

sojahseh · 08-23-2013, 04:30 PM

Quote:

Originally Posted by boyt911sc

Matt,

You are doing something different (wrong) if you could not install 915 transmission with the engine (with complete exhaust system). Let's go back when you dropped the engine/trans together. How did you remove the transmission from the engine? Did you have the exhaust (HE) and cross-over pipe on the engine prior to separating the transmission?

During a typical engine rebuild, everything is installed back to the engine except the muffler. Then the transmission is hook up with the engine (SOP) with the starter. Look closely what's preventing you from doing this routine procedure. Pay attention to the three (3) transmission studs with respect to the axis of the holes. Line them up on the same plane or axis to mate it.

Keep us posted.

Tony

Bear in mind I took the drive train out of the car several months ago, but I'm quite certain I removed the exhaust system first (I can't say that with 100% certainty though. The first step in this saga I have been moving through was to replace a mangled heat exchanger. In the process of removing it I broke three exhaust studs, necessitating an engine drop.

What seems to happen is the crossover pipe interferes with the clutch arm, forcing it into a position where you can't get the forks on the throwout bearing.

I will say, I am getting better at coupling and decoupling the two pieces, so trying again might yield different results.

If SOP is to install the exhaust minus the muffler, then there must be something I'm overlooking.

It also looks physically impossible to put the helper spring on once the transmission is mounted. True or False?

I look forward to hearing back...

-Matt

sojahseh · 08-23-2013, 04:57 PM

Quote:

Originally Posted by boyt911sc

Matt,

You are doing something different (wrong) if you could not install 915 transmission with the engine (with complete exhaust system). Let's go back when you dropped the engine/trans together. How did you remove the transmission from the engine? Did you have the exhaust (HE) and cross-over pipe on the engine prior to separating the transmission?

During a typical engine rebuild, everything is installed back to the engine except the muffler. Then the transmission is hook up with the engine (SOP) with the starter. Look closely what's preventing you from doing this routine procedure. Pay attention to the three (3) transmission studs with respect to the axis of the holes. Line them up on the same plane or axis to mate it.

Keep us posted.

Tony

Is removing the clutch arm part of the SOP during rebuild or reassembly?

yelcab1 · 08-23-2013, 05:17 PM

The clutch arm has to be removed from the rod before the engine can be pulled away from the transmission. You should be able to reinstall the cross over pipe after the engine is back in the car w/o any problems.

here is how I do it:

Engine with muffler and headers (and cross over pipe too) on a pallet
Lined up with transmission level to the engine
Grease up the input shaft, pull the transmission into the engine
Reach into the access port, engage the throwout bearing onto the fork
Grab both flanges on the tranny, turn them both toward the engine and slide the tranny in until you feel the engine and tranny engage. The last 1/2 inch, you need to tighten the nuts for the rest of the way.

Then, when the engine is back in the far, you attach the clutch arm and the clutch cable arm.

Really, this is not a hard task.

sojahseh · 08-23-2013, 05:52 PM

Just to be sure I'm on the same page as everyone here. This is the clutch arm that prevents me from sliding the transmission on. It get;s pushed back too far to be able to engage the clutch forks.

Is this what needs to be removed?

yelcab1 · 08-23-2013, 05:58 PM

That has to come off. A cir clip and sometimes a pin need to be removed. All you want to see is the shaft sticking out of the bottom of the gear box.

pete3799 · pete3799's Garage

the large release arm should be free to rotate and should not prevent you from mating them up. some are held on with a roll pin. the roll pin only prevents the arm from sliding down the shaft. It does not lock it the shaft.
Use some penetrating oil on it.

yelcab1 · 08-23-2013, 08:18 PM

Although I do not see a roll pin with this arm, some have had a roll pin that makes the arm interfere with the mating. Just remove it

boyt911sc · boyt911sc's Garage

Matt,

The clutch release lever is shown in your picture attached to the omega or helper spring. Normally after removing the circlip the clutch position lever (small arm at the bottom of the clutch release cross-shaft) slides down easily with the clutch release lever. But I've seen some clutch release levers get stuck on the clutch release cross-shaft.

Your clutch release lever does not have the pin found in older 915 transmission. It should slide down with very little resistance unless there is corrosion or irregularities on the cross-shaft. Check if the clutch release lever rotates freely on the cross-shaft. There should be no restriction on the movement (up/down). And in most cases, you have to help keep it in place otherwise, it would slide down the shaft.

Check your clutch release lever (big arm or lever) and find out if you could pull it out. Keep us posted.

Tony

Ronnie's.930 · 08-23-2013, 10:33 PM

Quote:

Originally Posted by sojahseh

It also looks physically impossible to put the helper spring on once the transmission is mounted. True or False?

-Matt

False - it can come on and off with the transmission mounted to the engine and with the engine/trans in the car (I've done it several times on a 930 transmission). However, getting the omega spring mounted and in position is one of those things that is difficult to figure out, but is actually incredibly easy once you "get it". I got help on the 930 forum the first time I worked with that thing because I was stumped by it.

Here is a link to my old omega spring thread -

HELP - Omega Spring

sojahseh · 08-25-2013, 05:07 PM

Ok, so the clutch release lever is not budging on the shaft. I can rotate it but not independent of the fork.

Is this arm supposed to be able to rotate on the shaft, and not move the clutch fork? It appears to be corroded in place. If previous versions of the 915 had a pin on this arm, is it not conceivable that this is a press fit?

Flat6pac · 08-25-2013, 06:13 PM

It should be free to rotate and to slide off. Use a pin point air chisel to viberate the arm loose from the shaft as corosion has it locked on the vertical shaft. There is a recess for the pin point on the bottom of the vertical shaft.
Mapp torch to heat it might also work but that arm should come off or be very free to rotate.
Bruce

yelcab1 · 08-25-2013, 06:23 PM

THen yours is rusted on the shaft

MAPP gas torch, use gloves
Or a small puller that can slide into that groove and pull it off.
Use MAPP gas and heat it up while wrenching on the puller. . It is not going to ruin anything. Do order 2 small rubber orings for that shaft when you go to put the arm back. And use some grease for installation so it does not rust.

Be careful with the heat, use gloves and remember that it is hot.

sojahseh · 08-25-2013, 07:00 PM

So that arm should spin freely all the way around on that shaft, and should fall off if the lower, smaller, splined one is removed?

What is the purpose of it?

pete3799 · pete3799's Garage

Yup should slide right off.
Leverage is the reason for it. If the clutch cable were hooked to the little arm you'd have to stand on the pedal to get it to move. It also provides a way to ensure you have free play in the cable so the fork doesn't put pressure on the throw out bearing.

sojahseh · 08-25-2013, 08:09 PM

Ok, so from the looks of it, mine was definitely corroded on there. Problem for me now is that instead of banging the arm off the shaft, I pulled the shaft out of the clutch fork.

At that point i was able to put the clutch arm with the shaft still in place, in a vice and get them apart.

Is there a rule of thumb for where on the shaft the clutch fork should be?