620 S Build

[CarYenta]

Car is almost here! In the meantime, I can't find a single 620 S with a 5 speed engine/transmission install guide or build blog other than the official Caterham guide.

 

Can someone point me in the right direction?

[pickles]

Hi CarYenta

 

I was asking myself the same question a few weeks back ... having just got a delivery of a 620R ... so am guessing you are in the same position as me ... you have a rolling chassis and then an engine/gearbox, plus a box of other bits such as exhaust etc. I have previously built a 360 so am familiar with the Duratec install, but this is slightly different in the sense that during a regular build the engine/gearbox, go in relatively early in the build, whereas this is right at the end. I am going to be installing the drivetrain in next couple of days so will shout out with any info I can. I have the SADEV gearbox but am expecting install will be pretty similar to the 620S.

Just looking at the engine bay and thinking back to my 360 build I can already envisage I may have to remove a few pieces such as engine mounts and duct work to squeeze the drivetrain in!

 

Pickles

[CarYenta]

1 minute ago, pickles said:

Hi CarYenta

 

I was asking myself the same question a few weeks back ... having just got a delivery of a 620R ... so am guessing you are in the same position as me ... you have a rolling chassis and then an engine/gearbox, plus a box of other bits such as exhaust etc. I have previously built a 360 so am familiar with the Duratec install, but this is slightly different in the sense that during a regular build the engine/gearbox, go in relatively early in the build, whereas this is right at the end. I am going to be installing the drivetrain in next couple of days so will shout out with any info I can. I have the SADEV gearbox but am expecting install will be pretty similar to the 620S.

Just looking at the engine bay and thinking back to my 360 build I can already envisage I may have to remove a few pieces such as engine mounts and duct work to squeeze the drivetrain in!

 

Pickles

Excellent! I really hope everything is smooth and easy.

[pickles]

23 hours ago, CarYenta said:

Excellent! I really hope everything is smooth and easy.

Trust me there always will be something that is NOT smooth and easy! That is the joy of owning a 7  

[CarYenta]

Step 1 complete, car delivered to garage!

 

[CarYenta]

Prepping engine bay. Removed intercooler and rotrex fluid can, engine mounts, moved some wiring and tubing around. Hoist getting prepped, car moved over a bit since my garage door opener motor was in the way Going to try to keep the radiator on.

[CarYenta]

Engine and transmission about to be mated. I managed to lift the engine out of the crate 180 degrees backwards, doh!

 

Questions:

Does the transmission spline and throw out bearing require any lubricant?

Do I put locktite on pretty much everything? Or nothing?

What is the engine mount torque of the main center bolt?

 

Cheers!

[IamScotticus]

Consider adding weight to the back of that hoist.

Get the cat about 15 inches high to clear the transmission angle or chalk the front wheels good and raise the rear.  Foam noodles, like pipe insulation, on all the frane tubes.  Remove the radiator.  Cover the head lamps.  When mating the trans, put some Sachs clutch grease on the splines.  When stabbing in the input shaft,  be as level as possible and don't let it hang (droop) on the disc splines and pilot (spigot) bearing.  Double check all eng and BH bolts and holes for mstching thread and depth BEFORE trying to mate.  Torque bell housing bolts evenly to spec wirh a proper torque wrench, no guessing here.

This is also a good time to plan for things like adding tunnel insulation,  access holes for gearbox oil filling, etc.  I highly recommend Allstar chassis stands. You want to move the car sideways, not the hoist.

 

Edited June 4 by IamScotticus

[CarYenta]

23 minutes ago, IamScotticus said:

Consider adding weight to the back of that hoist

Noted - the feet are quite longer than where the engine hangs. If it feels tippy at all I'll move the top arm a few notches back.

[CarYenta]

Mated the transmission tonight, decided to give the engine-in a go. Quickly realized that indeed, the radiator and oil cooler needed to be removed or else the hoist can't move for enough back. Managed to jam the transmission into the bottom frame rails as the box-bars at the bottom are quite a bit narrower than higher up. Jacked up the rear so ji could guide it in better for a re-try. Thought it was going to make it, but the supercharger and mount are barely in the way. Giving up for tonight and have to take that off.

 

I'm a little confused about:

1) when I pull the cap off the end of the transmission to mate the driveshaft, am I going to get a face full of transmission fluid??

2) how to attach the two wires at the top of the transmission

3) how to remove the hand brake handle to pull off the center console trim

4) the two bolts at the very bottom of the transmission bell housing are not used, right? They were attached to the dry sump skid plate.

Edited June 7 by CarYenta

[wdb]

These are super helpful. 

 

https://www.harborfreight.com/automotive/lifts-cranes-stands/3-4-quarter-ton-capacity-heavy-duty-load-leveler-67441.html

 

[TN_Scooter]

I just put my 7 together about a month ago. I would take the rear plug out and tip the engine and transmission to pour out the trans fluid. Use a large, clean bowl to pour the fluid into. Cover up the fluid until you are ready to refill the transmission. Should be no problem reusing the new fluid. Other option is removing the yoke from the drive shaft and using it as a plug while installing engine/transmission. Be sure to secure the yoke to the transmission before tilting it into the ending bay. Just my 2 cents.

[CBuff]

I can’t shed much light on the big items. But the handbrake should just slide out of the gator.  Raise the handbrake as high as you can and then raise the tunnel cover from the back and slightly slide it forward. Some folks on the forum say they had to loosen the handbrake cable (by diff / rear dedion ) to raise it enough. But I was able to get it done without that. 

[CBuff]

I got away with not loosening the handbrake cable. 

[CarYenta]

14 hours ago, CBuff said:

I can’t shed much light on the big items. But the handbrake should just slide out of the gator.  Raise the handbrake as high as you can and then raise the tunnel cover from the back and slightly slide it forward. Some folks on the forum say they had to loosen the handbrake cable (by diff / rear dedion ) to raise it enough. But I was able to get it done without that. 

The issue is my hand brake handle appears to be glued on. There are no grub screws. I have to take that off?

[CBuff]

My gator slips over the handle (just barely).  Get the gator collar to slip over the handle. It’s fiddly but works.  Not sure if you have an aftermarket handle or a overly tight gator 

[CarYenta]

18 minutes ago, CBuff said:

My gator slips over the handle (just barely).  Get the gator collar to slip over the handle. It’s fiddly but works.  Not sure if you have an aftermarket handle or a overly tight gator 

Oh interesting, I will try again! Stock handle.

[IamScotticus]

When you put the weight of that engine on the chassis,  it will drop the height.  Do you have clearance for the front suspension and hoist legs?

Like I said,  the chassis needs to be about 15" high so 1, the transmission angle will clear an 2, so you can get underneath and do everything you need to.  Trying to do this with the car on the floor is trouble.  Sorry if I come across rude, sorrry, I just care, a lot.  An accident will ruin a lot of the fun. I know.

 

Oh, while I'm being so charming, here's another criticism,  that blue painter's tape isn't enough to protect the chassis.  A gentle bump has enough weight behind it to cut through that.  Get some 1" or larger plastic wire conduit to slide over.

It's something you will use again next time youre wrenching. 

 

Edited June 8 by IamScotticus

[IamScotticus]

On 6/3/2025 at 11:57 PM, CarYenta said:

Questions:

Does the transmission spline and throw out bearing require any lubricant?

Use a light smear of clutch grease on the splines, like that from Sachs. I have a tube if you need.  The bearing is pre-lubed and adding anything to it can destroy what it already has.

 

Do I put locktite on pretty much everything? Or nothing? 

Nothing where torque values need to be specific.  Anything under 15 lbsft should be OK for blue LT.  Lock washers and anti-seize is better.  But you don't want anything distorting your torque values.  Torque values aren't so much to keep fasters from walking out, they are there to ensure a part is tightend evenly for the sake of the component to function properly. Use other things like lock washers and safety wire to prevent walking.  Regular spanner checks will show you what is walking out.

 

What is the engine mount torque of the main center bolt?

Keep only snug until all weight is loaded on the chassis and on the ground. Then refer to manual for values.

My opinion on the rubber mount tightening is, just 6" wrench tight with a nylock nut and washer on bottom. Coat the bolt to protect from corrosion as it's exposed to elements and its an electrical ground path.  Wire a ground strap from the bolt head to the chassis so the aluminum body pannel doesn't get eaten up from electrolysis.

 

 

Edited June 8 by IamScotticus

[CarYenta]

20 hours ago, IamScotticus said:

When you put the weight of that engine on the chassis,  it will drop the height.  Do you have clearance for the front suspension and hoist legs?

Like I said,  the chassis needs to be about 15" high so 1, the transmission angle will clear an 2, so you can get underneath and do everything you need to.  Trying to do this with the car on the floor is trouble.  Sorry if I come across rude, sorrry, I just care, a lot.  An accident will ruin a lot of the fun. I know.

 

Oh, while I'm being so charming, here's another criticism,  that blue painter's tape isn't enough to protect the chassis.  A gentle bump has enough weight behind it to cut through that.  Get some 1" or larger plastic wire conduit to slide over.

 

It's something you will use again next time youre wrenching. 

 

Thanks for the tips! I'm here to learn, not for praise so no worries.

 

The blue painters tape ripped 😂 so I added a few extra layers. Managed to not actually scrape it however.

I raised the front of the car up as suggested and that definitely helped in getting the propshaft lined up as well.

The top tunnel gaitor I didn't realize was elastic, so it made it over the hand brake no problem, silly me. Had to remove 6 carefully placed zip ties to unplug the heated seat connectors :/

 

I put a pan under the transmission plug and drained the fluid as recommended, worked great. Except then I had to remove the engine again to change the chain lengths, plugged the hole, put engine back into the car at a large tilt, and unplugged it expecting no fluid to come out. Suffice it to say, that was real dumb! Poured out all over me.

 

Alas, engine is in! Engine mounts on, transmission mounts not quite all the way on. I'm going to install one of the 4 carrier bolts upside down (nut inside the car) as there's two or three extremely stiff wires blocking the bolt from coming in through the top. I guess people in England have to worry about MOT inspection but not I. 

 

I had to take off in total: the intake manifold, radiator, intercooler, oil cooler, super charger reservoir, supercharger, alternator, and two pulleys. Also, I was as close as I could get the hoist at one point, it was touching the sway bar, so had to manually push to swing the engine over the upper cross members. I'd recommend anyone thinking of the smaller harbor freight 1 ton hoist to get one with a longer reach.

 

The transmission is a little skewed and is touching the tunnel on the left side. I plan to play around with a pry bar while tightening to see if I can get it centered better.

 

Here's going in before removing the upper left alternator and just below black pulley, with a jack under the transmission to help level it with the propshaft:

 

 

From underneath helping align with the prop shaft:

 

 

My askew transmission:

 

Engine in from top with a few things being reinstalled:

 

And done for the day

Edited June 9 by CarYenta